Planning guide · updated November 2026
Los Altos Hills is a semi-rural foothill town above Los Altos and Palo Alto, with large lots, rolling terrain, oak woodland and long views of the Bay. Most of the building here is new custom homes, either on open lots or replacing an older house. The Town has no formal architectural review and welcomes a wide range of styles, but every new house goes through site development review with story poles and a public hearing, and the size of the house is set by the slope of the lot. Below is how we plan new homes in Los Altos Hills, so the design and the schedule allow for that review before the footprint is fixed.
Harrod Built takes on new custom homes and full rebuilds on the Peninsula and in the South Bay, including Los Altos Hills. Looking at a lot or a plan set in Los Altos Hills? Phone 805-712-8993 or use the form at the bottom of this page.
The short answer
In the Town of Los Altos Hills, a new house needs a zoning permit and a site development permit from the Planning Department before the Building Department will take plans. The path starts with a meeting with a Town planner and a required pre-application meeting, then a formal application with a geotechnical review and comments from Town committees. Every new residence gets a public hearing, either a Fast Track hearing run by the Planning Director or a Planning Commission hearing, after story poles go up and neighbors are notified. How big the house can be comes from the lot’s slope, through the Lot Unit Factor and the maximum floor area and development area worksheets. (we confirm per lot)
1. Who reviews what
A small town with a thorough site review
Los Altos Hills is its own incorporated town with a combined Planning and Building staff at Town Hall. It is easy to confuse with the City of Los Altos below it, which has its own design review and permits, and with unincorporated County pockets that share a Los Altos Hills mailing address. On a new house, several groups weigh in:
| Office or group | What it handles on a new home |
|---|---|
| Planning Department | The initial and pre-application meetings, the zoning permit and site development permit, story pole sign-off, hearing notices, conditions of approval and Heritage Oak removal permits. |
| Fast Track hearing or Planning Commission | The public hearing for every new residence. Fast Track hearings are run by the Planning Director; larger or contested projects go to the Planning Commission. |
| City Council | Appeals, and a short window to review projects approved through Fast Track or by the Planning Commission. |
| Town committees | The Pathways, Open Space, Environmental Design and Protection, and History committees comment on site development plans. |
| Engineering and the Town Geologist | Grading, drainage, driveways, erosion control and the geotechnical review for new homes, run alongside planning review. |
| Building Department | Plan check through the eTRAKiT portal, inspections and the final. |
| Fire | The Santa Clara County Fire Department reviews access, hydrants and sprinklers; the Los Altos Hills County Fire District runs local wildfire programs. |
| County Environmental Health | Septic permits, and the review when a new home on septic may have to connect to sewer. |
Summarized from Town of Los Altos Hills Planning, site development, Building, Public Works and committee pages and policy handouts, read November 2, 2026.
On a first call we confirm the jurisdiction, pull any past worksheets and permits for the parcel, and check recorded easements, pathways, creeks and the septic or sewer situation. Our page on custom home building in Palo Alto and the nearby Peninsula towns describes the kind of homes we take on in this part of the Peninsula. (we confirm per lot)
2. Site development review
No style rules, but a close look at the land, views and neighbors
The Town’s Site Development Review Process handout explains that Los Altos Hills has a policy of no formal architectural review, to encourage a diversity of building styles. What it reviews instead is how the house fits the site and the neighborhood. According to the site development review FAQ, every new structure, exterior change and new paved coverage is reviewed for compliance with the Zoning and Site Development ordinances, and the reviewers look at height and placement on the site, views and privacy for neighbors, how visible the lot is and what screening it needs, and whether the house follows the natural contours with minimal grading, minimal paving and the existing trees kept. Stepped foundations are encouraged on sloped sites and can be required.
Projects are sorted into levels of review. Smaller work can be approved by staff or at a noticed staff hearing, while all new residences go to a public hearing, either Fast Track or the Planning Commission. The Fast Track Guide for New Residences comes with a checklist that scores how closely a new house follows the Town’s development philosophy: a low score makes the project eligible for a Fast Track hearing run by the Planning Director, a middle score may be sent to the Planning Commission, and a high score must go there. Fast Track also requires that the project meets the codes without a variance, has no substantive neighborhood opposition and that the owner accepts the conditions of approval in writing. Very large homes covered by the Estate Homes Ordinance are not eligible for Fast Track at all and carry larger setbacks and a landscape screening plan reviewed by the Commission.
Approvals can be appealed to the City Council within a set window, and the Council can also call up projects approved through Fast Track or by the Commission. We plan the schedule with that window in mind, because the building permit can’t be filed until it closes.
3. What sets the size of the house
Slope, Lot Unit Factor, floor area and development area
Los Altos Hills does not use a simple floor-area ratio. The Town’s MFA and MDA worksheets work from the lot itself:
- Average slope. Measured from the contours of a topographic survey within the net lot area, which leaves out road and access easements.
- Lot Unit Factor. The net area reduced as the slope increases, so a steeper lot of the same size gets a smaller factor.
- Maximum floor area. The enclosed floor area allowed, calculated from the Lot Unit Factor and the slope. Basements that meet the Town’s definition are generally not counted.
- Maximum development area. A separate cap that counts the house footprint plus driveways, parking, patios, decks, walks, pools, sports courts and other hard surfaces.
- Small or very steep lots. When the Lot Unit Factor falls below a set threshold, a Conditional Development Permit is needed and the allowances can be limited further.
Development area is where many first designs run out of room. The Development Area Policy explains that driveways, required parking, fire truck turnarounds, sports courts and raised decks look like development regardless of the surface, so permeable materials earn only limited credit, and only when a civil engineer shows the runoff will not increase. A long driveway on a sloped lot and the fire turnaround it needs can take a large share of the allowance before the pool and patios are drawn. We run the worksheets and lay out the driveway early, and our hillside lot guide covers the construction side of a sloped site.
4. Meetings and the application
What the Town asks for before the hearing
The Town’s site development process pages lay out the steps. After an initial meeting with a Town planner, a pre-application meeting is required, and the planner asks for completed MFA and MDA worksheets, a topographic survey, a site plan, floor plans, building sections and elevations. At that meeting the planner issues a checklist specific to the project, listing what the formal application has to include. Engineering staff join when the project changes grading, drainage or the driveway, or involves road or pathway dedications.
- Permits filed together. The zoning permit and site development permit are processed at the same time.
- Geotechnical review. New residences need a geotechnical report reviewed by the Town Geologist alongside the planning review.
- Committee referrals. Plans go to the Pathways, Open Space, Environmental Design and Protection, and History committees for comment.
- Comment letters. Staff combine comments from departments, outside agencies and committees into one letter, and a project often goes through more than one round of revisions.
- Neighbors. The Town recommends sharing plans with neighbors before filing, since a concern raised early is easier to resolve in the design.
That is close to a full schematic design with a real survey under it. We estimate the house from this set, so the owner knows what the approved design will take to build before construction drawings are paid for.
5. Story poles and the hearing
Showing the house on the land before anyone votes
The Town’s story poles and hearing notice page explains that once a project is complete and needs a hearing, staff tell the applicant to put up story poles, and hearing notices go out only after staff have inspected and approved them. The Story Pole Policy sets the details:
- Who sets them. The project surveyor or civil engineer locates the corners, and the pole heights show the finished height of the house with grading accounted for.
- Materials. Rigid lumber or metal poles, with a band of orange snow fencing outlining the ridgelines and eaves. Plastic piping is not accepted.
- Everything else on the ground. Pools, sports courts, driveway changes and open space easements are outlined with stakes and ribbon, and every tree proposed for removal is marked.
- How long they stay. Until the hearing and the appeal period are over, and longer if the project is appealed. The applicant provides photos of the installed poles.
- Exemption. Smaller, lower single-family homes that need no variance can skip poles if a large three-dimensional rendering is posted next to the hearing notice.
Notices are mailed to nearby owners and the hearing follows a short notice period. The owner or a representative should attend, since the hearing officer or Commission may ask questions or request changes. We help owners plan the pole installation and the hearing date into the schedule, because nothing moves until the poles are approved.
6. Grading, foundations and basements
Stepping the house down the hill
The Town’s Grading Policy asks that grading be the minimum needed and that houses keep the basic landform of the site. Steeper building sites require step-on-contour, daylight or pole foundations. The policy prefers cut, which lowers the profile of the house, over fill or tall foundation walls, which raise it, and it sets limits on how deep cuts and fills can go for the house, accessory buildings, pools, sports courts, driveways and yards. The lowest floor is expected to stay close to the existing grade so the house steps with the slope, and no grading is allowed right along the property lines.
- Basements. Under the basement ordinance, a level that sits below the building with most of its perimeter underground and a floor above set close to grade is treated as a basement and generally not counted as floor area. Daylight basements still have to meet height and setback rules and the Grading Policy.
- Drainage and erosion control. A final drainage plan and an erosion control plan are approved by Town engineering before plans are accepted for building plan check.
- Construction operations. A grading and construction operation plan covers truck traffic, dust, noise, material storage, sanitation and parking for crews.
- Height certification. A civil engineer or licensed surveyor certifies the height and location of the house before the final inspection.
On a sloped Los Altos Hills lot, the foundation, retaining walls, export of soil and the driveway are often the largest site costs. We estimate them from the soils report and the grading plan rather than as allowances. Our Title 24 overview covers the energy side of a new house.
7. Oaks, easements, pathways and screening
The parts of the lot the Town wants kept
The Town’s trees and shrubs page explains that any oak above a set trunk size is a Heritage Oak, protected and removable only with a zoning permit from the Planning Department. The tree fencing requirements require every significant tree to be fenced at its dripline with chain link before any grading begins, with the fencing inspected by Town staff and kept in place for the whole job. No equipment, vehicles or debris can be stored inside the dripline, and no trenching is allowed beneath it.
- Open space easements. According to the open space easement guide and the standard conditions, the Town may require an open space easement over steep parts of the lot, Heritage Oaks or creek corridors. Land in the easement stays undeveloped, so it shapes where the house, driveway and yard can go.
- Pathways. Where the Town’s Master Path Plan shows a path along or across the lot, the Pathways Committee can recommend a pathway easement or construction of the path as a condition of approval.
- Landscape screening. After framing, a landscape screening and erosion control plan is reviewed at a Site Development hearing, with input from the Environmental Design and Protection Committee, and the screening has to be planted before the final inspection.
- Open space and habitat. The Open Space Committee comments on easements, creeks and natural areas during review.
Our landscape company, Paso Robles Landscaping, plans screening, planting and irrigation that fit the approved plan and the Town’s water-efficient landscape rules.
8. Lighting, roofs and other conditions
Standard conditions on a new Los Altos Hills home
The site development review FAQ lists the Town’s standard conditions for new residences, and several shape the design itself:
- Outdoor lighting. Fixture specifications are approved by Planning before plan check. The Outdoor Lighting Policy calls for shielded, low-glare fixtures that keep light from spilling onto neighbors, and limits lights within the setbacks to driveway fixtures unless more are needed for safety.
- Skylights are designed to reduce emitted light, with no lighting in skylight wells.
- Pools. Pool lighting is kept low and pool equipment is enclosed on all sides for noise and screening.
- Roofing. Class A roofing is required on new construction.
- Green building. New residences have to meet a recognized green building standard, such as Build It Green or LEED for Homes.
- Roads and pathways. The owner repairs any construction damage to pathways, driveways and roads, and the access road keeps the width and clearance fire trucks need.
We read the conditions of approval line by line before we finalize the estimate, because lighting, roofing, screening and road repair all carry real cost.
9. Septic, sewer and utilities
Checking the wastewater path early
Parts of Los Altos Hills are on public sewer and parts are on septic. The Town’s septic system page explains that septic permits are handled by the County of Santa Clara Department of Environmental Health, and that new residences and major additions may have to abandon the septic tank and connect to the public sewer. On the sewer side, the sanitary sewer page notes that the owner is responsible for the lateral from the house to the main, including the relief valve and backflow device.
- Work in the street. Utility connections, driveway approaches and other work in the public right-of-way or public easements need a Town encroachment permit; see the encroachment permit page.
- Roadside trees. Property owners maintain the trees and vegetation in the right-of-way along their frontage.
- Electrification. The Town’s building electrification page describes a climate action plan that prioritizes all-electric homes, with heat pump water heating and space heating, induction cooking and electric dryers.
A sewer connection on a long frontage or a new septic design on a sloped lot can change the budget and the schedule, so we confirm the path with the Town and County before the estimate is final.
10. Fire and wildfire
Access, sprinklers and the wildland edge
Much of Los Altos Hills is wooded foothill land. Check the address on the State Fire Marshal’s fire hazard severity zone maps; a mapped lot brings in the state wildfire construction chapter, which our fire hazard severity zone guide explains, and the Town lists the construction requirements for wildfire risk areas on its building permits and forms page. Standard conditions also allow the Fire Department to require sprinklers or a hydrant, and the driveway has to keep the width and vertical clearance a fire engine needs.
The Santa Clara County Fire Department plan submittal page explains that fire sprinkler plans are a separate submittal by a licensed contractor after the building permit is issued, with recent water flow data from the water purveyor. The Los Altos Hills County Fire District runs defensible space, brush chipping and home ignition zone programs for residents. We plan the driveway, turnaround and water supply with the fire review in mind, since they also count toward development area.
11. The building permit
After the conditions are cleared
Once the site development approval is final and the appeal period has passed, the conditions that have to be met before plan check are signed off, and construction drawings can be submitted. The Town’s Building Department page explains that building permits are filed electronically through the eTRAKiT portal, where the owner or contractor sets up a profile first.
- Before plan check. Lighting specifications, the final drainage plan and the erosion control plan are approved first.
- Tree fencing is inspected before any grading starts.
- Inspections are booked several days ahead, there are no same-day inspections, and none are scheduled on Fridays.
- Work hours. The hours of construction notice limits construction to weekday and Saturday daytime hours, with no heavy equipment on Saturdays and no work on Sundays or listed holidays. Crew parking stays on the property, never on the pathways.
- Time limits. Building permits carry a construction completion time limit, with limited extensions available on request before it runs out.
- Energy and green building. Energy compliance and the CALGreen checklist go into the plan set.
The state’s 2025 Energy Code applies to permit applications filed on or after January 1, 2026.
12. Order of steps
How we usually sequence a Los Altos Hills new home
| Stage | What it involves | What tends to drive timing |
|---|---|---|
| Lot check and initial meeting | Confirm the parcel is in the Town (not the City of Los Altos or unincorporated County), pull past MFA and MDA worksheets and permits, and meet a Town planner. | Quick once the address is known. |
| Survey, slope and allowances | Topographic survey, average slope, Lot Unit Factor, maximum floor area and maximum development area, plus easements, pathways, creeks and Heritage Oaks. | Surveyor calendar and lot complexity. |
| Concept and pre-application | A massing that follows the contours, with the worksheets, site plan, floor plans, sections and elevations taken to the required pre-application meeting. | How many options the owner wants to compare. |
| Application and comment letters | Zoning and site development permits filed together, the geotechnical report to the Town Geologist, committee referrals and one or more rounds of comment letters. | Correction rounds across departments and committees. |
| Story poles and hearing | Poles and netting set by the surveyor or civil engineer, staff sign-off, mailed notice, then a Fast Track or Planning Commission hearing and the appeal window. | Pole installation, the notice period and the meeting calendar. |
| Building permit | Drainage, erosion control, lighting and construction operation plans cleared, then construction drawings through eTRAKiT. | Plan check rounds and condition sign-offs. |
| Construction and final | Tree fencing inspected before grading, inspections booked ahead, landscape screening reviewed after framing, and height certified before the final. | Construction, weather and inspection scheduling. |
A typical sequence for a new house in Los Altos Hills; slopes, trees, septic and the level of review can each change it.
Our custom home timeline guide lays design, approvals and construction out on one calendar, and our owner-builder comparison is worth a read for anyone considering running the job themselves. Neighboring towns work differently, and our guides for Los Altos, Palo Alto, Woodside and Portola Valley, Atherton, Saratoga and Los Gatos cover their rules.
13. Before you design
Questions to answer about your property
- Is the lot in the Town of Los Altos Hills, the City of Los Altos or unincorporated County?
- What are the average slope and Lot Unit Factor, and what floor area and development area do they allow?
- Is there a past MFA and MDA worksheet or permit history for the parcel?
- How much development area will the driveway, parking and fire turnaround take?
- Will the house likely score for Fast Track, or go to the Planning Commission?
- Which Heritage Oaks and significant trees are on or next to the lot, and where are their driplines?
- Are there steep areas or creek corridors that could become an open space easement?
- Does the Master Path Plan show a pathway on the property?
- Is the lot on sewer or septic, and will a new house have to connect to sewer?
- Is a basement planned, and what will the soils report and grading plan require?
- Is the lot in a fire hazard severity zone, and how will fire access and water supply work?
- Who will talk with the neighbors before filing?
Owners who already have an architect send us the drawings and we estimate and build from them; owners starting from scratch can have Harrod Drafting & Design, our sister studio, draw the house and the permit set.
How we help
What Harrod Built brings to a Los Altos Hills new home
Harrod Built (CSLB #986950) is a family-run general contractor building on the Peninsula, in the South Bay and on the Central Coast. On a Los Altos Hills new home, our role usually covers:
- Lot review first. Jurisdiction, slope, floor and development area, easements, pathways, trees, septic or sewer and fire access, all mapped before we write an estimate.
- Pricing during site development review. We estimate from the pre-application and hearing sets, while changes are still easy to draw, and again on any revision the Town asks for.
- Hillside site work estimated from real plans. Foundations, retaining walls, soil export, drainage and the driveway taken from the soils and grading documents, not allowances.
- Story poles and the hearing. Coordinated with the surveyor so the poles go up on time and stay until the appeal window closes.
- Trees protected. Dripline fencing, staging and access laid out with the arborist and kept in place through construction.
- Conditions tracked. Lighting, drainage, erosion control, screening, road repair and height certification followed through to the final.
- Design support. Harrod Drafting & Design can draw the house and the permit set, or we build from the plans of your own architect.
- Landscape. Paso Robles Landscaping, our landscape company, handles screening, planting, irrigation and hardscape to the approved plan.
- On site. Our project manager and site lead keep neighbors informed, stay inside the Town’s work hours and update the owner week by week.
Before hiring any builder, look up the license on the state license lookup; the CSLB’s advice on hiring a contractor and our article on how to check a CSLB license explain what to look for. Nearby we also build in Palo Alto, Atherton, Woodside and Portola Valley, Los Gatos and Saratoga, and farther south in Monterey, San Luis Obispo and Santa Barbara counties, through general contracting or design-build. Our process page shows the steps from estimate to move-in, and our contract type comparison explains fixed-sum and cost-plus agreements. For the local market, see our Palo Alto and nearby Peninsula page.
Weighing a lot or a new home plan set in Los Altos Hills? Send us the address and whatever drawings exist. We look at the slope and floor area allowances, the review path, the grading, the trees and easements, septic or sewer and fire access, then send back a written estimate. Phone 805-712-8993 or reach us here.
Sources: Town of Los Altos Hills site development process pages, story poles and hearing notice page, Story Pole Policy, Fast Track Guide for New Residences, site development review FAQ and process handout, Development Area Policy, Estate Homes Ordinance, MFA and MDA worksheets, basement ordinance, Grading Policy, tree fencing requirements, Outdoor Lighting Policy, open space easement guide, Building Department and building permits pages, hours of construction notice, building electrification page, Public Works septic, sewer, trees and encroachment pages, and the Town committee pages. Santa Clara County Fire Department plan submittal page and the Los Altos Hills County Fire District. State sources: OSFM fire hazard severity zone maps, the CEC’s 2025 energy standards and the CSLB, all reviewed November 2, 2026. This page is a general overview, not legal or code advice; what applies to a given lot is decided by the Town of Los Altos Hills and the other agencies involved.
Who issues building permits in Los Altos Hills?
The Town of Los Altos Hills Building Department, after the Planning Department approves the zoning and site development permits for a new house. The City of Los Altos is a separate city with its own permits.
Does Los Altos Hills have design review?
The Town has no formal architectural review and allows a wide range of styles. Instead, every new house goes through site development review, which looks at how the house fits the land, its height and placement, views and privacy for neighbors, grading and the trees kept.
What is Fast Track in Los Altos Hills?
A public hearing run by the Planning Director for new homes that score low on the Town’s Fast Track Guide checklist, meet the codes without a variance, have no substantive neighborhood opposition and whose owners accept the conditions. Other new homes go to the Planning Commission.
How big a house can I build in Los Altos Hills?
It depends on the lot. The Town calculates the average slope from a topographic survey, then a Lot Unit Factor, and from those the maximum floor area and the maximum development area, which also counts driveways, patios, pools and other hard surfaces.
Do I need story poles in Los Altos Hills?
New homes that go to a hearing put up story poles with orange netting outlining the roof, set by a surveyor or civil engineer and approved by staff before notices are mailed. Some smaller, lower homes can post a large rendering instead.
Can I remove an oak to build in Los Altos Hills?
Heritage Oaks are protected and need a zoning permit from the Planning Department to remove. Trees to be kept are fenced at the dripline before grading, and the Town may also ask for an open space easement over oak groves, steep slopes or creeks.
Planning guides
Budget and planning guides
Building or remodeling in Los Altos
Design review, the Zoning Administrator, daylight plane, protected trees and the City permit path.
Building or remodeling in Woodside and Portola Valley
ASRB and ASCC design review, story poles, geology, significant trees, grading and the fire district.
Building or remodeling in Atherton
Zoning clearance, special structures permits, heritage trees, basements, drainage and construction rules.
Building or remodeling in Palo Alto
Individual Review for two-story homes, protected trees, flood zones, basements and deconstruction.
Building or remodeling in Saratoga
Saratoga’s design review paths, hillside rules, protected trees and County Fire.
Building or remodeling in Los Gatos
Architecture and Site review, hillside standards and story poles in the Town.
Building on a hillside lot
Foundations, grading, drainage and access on a sloped lot.
How long a custom home takes
Design, approvals, permits and construction laid end to end.
Start your project
Planning a new home in Los Altos Hills? Tell us about your property.
A few details help us call you back with useful answers about budget, schedule and permits.
805.712.8993michael@harrodbuilt.com
1345 Riverside Ave, Paso Robles, CA 93446
CSLB License #986950
