The difference between these seven towns is not speed. It is where the gate sits. The same second-story addition goes straight to plan check against objective standards on a conforming Menlo Park lot, with no public design process normally triggered. It goes before a five-resident commission in Portola Valley the moment it reaches 400 square feet. It lands in a hearing in Los Altos Hills simply because it is a new residence. Place the lot in the right tier first. Talk about schedule second.
Who this is for
- Buyers purchasing a house they intend to change — a gut renovation, a second story, a teardown. The purchase price is one line. The approval path decides when you can break ground.
- Buyers choosing between towns — at the same budget, the regulatory difference between Palo Alto, Menlo Park, and Woodside often moves your timeline more than the houses do.
- Owners about to commission drawings — you want to know whether your scheme triggers a public hearing, and whether the architect or the surveyor comes first.
- Investors running a rebuild pro forma — carrying cost during entitlement is part of the total, and it is the part most models leave out.
Three questions that decide your path
One: does this town have a design-review gate at all?
This is the sharpest divide among the seven, and it tracks neither wealth nor strictness.
Los Altos Hills states it plainly in its own process handbook: the Town has maintained a policy of having no formal architectural review, in order to encourage a diversity of building styles and individual expression. Atherton likewise has no standing design review board. Menlo Park runs conforming lots straight into building-permit plan check against objective standards — FAR, lot coverage, daylight plane, setbacks. The code hangs its public-process trigger on substandard lot width, depth, or area rather than on the design itself, and local practitioners describe that path as carrying no design review step. Los Altos began loosening with its 2023 housing element and finished the job in July 2025, repealing its subjective design review ordinance for single-family construction in favor of objective standards. The same lot has a different answer on either side of 2023.
Palo Alto offers two routes. Meet the city's two-story objective design standards in full and you skip the hearing and go to plan check. Depart from them for design freedom and you file for Individual Review, which buys flexibility at the price of written neighbor notice, a comment period, and the possibility of added conditions.
Only two of the seven maintain a standing design review body: Portola Valley's Architectural & Site Control Commission (ASCC) and Woodside's Architectural and Site Review Board (ASRB). They are not the same kind of body. The ASCC is five volunteer town residents, focused on how proposed plans fit the unique conditions of the site and neighborhood — in that town, the people evaluating what your house looks like are your future neighbors. The ASRB is advisory: it makes a recommendation, and the Planning Director or Planning Commission issues the decision, delivered as an action letter.
Two: the trigger thresholds differ by a factor of five
Say you have bought a house and want to add an 800-square-foot single-story guest suite.
In Portola Valley that goes to the ASCC: the threshold there is any building or addition of 400 square feet or more, or two stories or more. In Woodside, if the lot sits outside the scenic corridors and Western Hills, 800 square feet falls under the 2,000-square-foot line and stays at staff level — but only if it is also under 30 percent of maximum total floor area and consistent with the town's residential design guidelines. Inside those areas the line drops to 1,000 square feet, and any building on a visible ridge line goes to conceptual plus formal ASRB review regardless of size. In Los Altos Hills, 800 square feet of floor area is under the 900-square-foot administrative ceiling, but the matrix reads three dimensions at once — floor area, development area (all disturbed ground, administrative ceiling 3,000 square feet), and grading volume (administrative ceiling 250 cubic yards) — and the highest of the three sets your tier. In Menlo Park what decides your path is not floor area but the lot itself: new construction or extensive remodeling on a lot with substandard width, depth, or area requires Planning Commission use permit or architectural control approval first. In Atherton, what pulls a project to the Planning Commission is a specific list — height between 30 and 34 feet, removal of a protected tree, a variance — and a conventional guest suite is usually not on it.
The same drawing is a hearing in one town and an over-the-counter permit in the next. Behind that sits a difference in what each town is protecting. Portola Valley is regulating added mass in a valley landscape, so the threshold sits very low. Woodside is regulating whether the project can be seen from a scenic road, so location is assessed before size.
One anti-avoidance clause is easy to miss: Woodside's code counts project size and scope cumulatively while building permits are open, with accessory dwelling units excluded. Splitting one large addition into several small ones does not work there.
Three: every town has one technical gate of its own
This is the layer buyers most often miss, because it does not appear on the flowchart — and it is often what actually sets the schedule.
In Palo Alto the gate is uncertainty itself: Individual Review runs on notice, a comment period, and a planning director decision, and neighbor response is a variable. In Atherton it is trees, groundwater, and basements. The tree protection zone radius equals ten times the trunk diameter, so a single mature heritage oak fences off a substantial patch of untouchable ground, and groundwater dewatering is allowed in only one two-week window per year. How those three constraints end up deciding how large a house can be is worked through separately in what an acre in Atherton actually lets you build.
Portola Valley also carries a materials constraint that runs alongside the approval track: since January 2022 the town's home hardening ordinance has required Class A roofing, noncombustible siding, noncombustible deck walking surfaces (wood composites such as Trex and TimberTech are not permitted), noncombustible fences and gates within 10 feet of the home, and enclosed eaves. Specify to that standard from the start — see what fire compliance requires of a hillside owner every year.
In Portola Valley the gate is geology: new residential construction and additions over 500 square feet must be referred to the Town Geologist, and the town's land use policies rest on a geologic map and a movement-potential map adopted in 1974. Departing from those policies requires a Planning Commission hearing — and only after the Town Geologist has reviewed the project and recommended approval.
Woodside stacks three. First, visibility: the code defines scenic corridors as land visible from the driving surface of two state-designated scenic highways (Skyline Boulevard and Interstate 280) and eight locally designated roads (Kings Mountain Road, Mountain Home Road, Woodside Road, Whiskey Hill Road, La Honda Road, Portola Road, Cañada Road, Sand Hill Road) — and explicitly includes land that would be visible if existing vegetation were removed. Second, the Natural State calculation: the topographic survey must highlight all slopes over 35 percent, those areas are subtracted from lot area, and the average slope of the remainder is computed; parcels over an acre averaging 12.5 percent or steeper need a separate Natural State plan. Third, the fire district: Woodside Fire Protection District requires its own separate online submittal, and proof of that filing has to be included in the town package — the same fire regime that makes insurance hard to place around Woodside.
In Los Altos Hills the gate is story poles. The policy is unusually firm. Poles go up before the project is noticed and no later than 10 days before the hearing; they must be built of rigid material such as lumber or metal (plastic piping is not accepted), carry a two-foot band of orange snow fencing outlining the proposed ridges and eaves, and stay standing until the hearing is over and the appeal period has run. The policy says it directly: public notices will not be mailed, and hearings will not be held, until the staking has been completed and approved by staff. In this town a set of poles can stall your entire schedule. The policy does leave one exit that matters to buyers: a single-family residence no taller than 19 feet, no larger than 4,000 square feet of floor area, and seeking no variance or exception is exempt from poles, provided a rendering of at least 24 by 36 inches is posted beside the hearing notice.
The seven towns' approval paths, side by side
Read the table as one sentence: the three hill towns — Los Altos Hills, Portola Valley, Woodside — will each put your project into some form of public process, but they stop you at different places. Los Altos Hills stops you at "every new residence goes to a hearing" and at story poles. Portola Valley stops you at a 400-square-foot threshold and geologic review. Woodside stops you at visibility and a two-stage design review. Palo Alto, Menlo Park, Atherton, and Los Altos each offer some version of a comply-and-skip-the-hearing route, and the price is accepting the objective standards in full.
| Town | Who reviews the design | What triggers a public process | The town's own technical gate |
|---|---|---|---|
| Palo Alto | No standing review board; a two-track system | New second story or second-story addition; meeting the objective design standards skips the hearing, departing from them means Individual Review | Written neighbor notice and comment period, with real uncertainty in the outcome; no story pole requirement found in the sources reviewed |
| Menlo Park | Conforming lots go to plan check against objective standards; design review sits with the Planning Commission and is triggered only by a substandard lot | Substandard lot width, depth, or area, which requires a use permit or architectural control approval first | Confirm jurisdiction first: West Menlo Park, Menlo Oaks and similar county pockets permit through San Mateo County; no story pole requirement found in the sources reviewed |
| Atherton | No standing design review board | A specific list only: height of 30 to 34 feet, protected tree removal, variances | Trees, groundwater and basements as three technical reviews, plus a statutory completion deadline with penalties; no story pole requirement found in the sources reviewed |
| Los Altos | Subjective design review repealed July 2025, replaced by objective standards | New two-story homes and one-to-two story conversions go to a Zoning Administrator noticed meeting | The rules have moved sharply and the answer differs on either side of 2023; story poles were dropped with the 2023 housing element |
| Los Altos Hills | Town states in writing that it holds no formal architectural review | All new residences go to the Planning Commission or Fast Track; additions tier by floor area, development area and grading volume | Notices are not mailed and hearings are not held until staking is approved; two permits, site development then building, and the City Council may overturn approved projects |
| Portola Valley | ASCC, five volunteer town residents | Any building or addition of 400 square feet or more, or two stories or more | Mandatory Town Geologist review, with land use policy resting on a 1974 geologic map; perimeter staking required and poles may be requested |
| Woodside | ASRB (advisory), conceptual review then formal review | 1,000 square feet inside scenic corridors and Western Hills; 2,000 square feet or more than 30 percent of maximum total floor area outside them; any size on a visible ridge line | Visibility determination, Natural State math after subtracting 35 percent slopes, separate fire district filing; poles required by code but not at the conceptual stage |
What to take from it: the same 800-square-foot single-story addition is an ASCC hearing in Portola Valley because the threshold there is 400 square feet, and an over-the-counter permit outside Woodside's scenic corridors because the threshold there is 2,000 — a five-fold gap that decides not how fast you move but whether you sit in a meeting at all. So the table should change the order in which you investigate. Most buyers ask whether a town is fast. The better sequence is three questions. Is my lot above the trigger line? Does this town have a design review gate? What is this town's technical gate? The first two decide whether you sit in a hearing. The third decides which consultant you hire first — the geologist in Portola Valley, the surveyor in Woodside, the arborist in Atherton, and in Los Altos Hills the surveyor or civil engineer who sets the story pole corners.
Putting approval time into the total: two real MK Group situations
The first is a century-old house in Old Palo Alto. Built in 1926, exactly one hundred years old in 2026, listed above $8M on a roughly 10,000-square-foot long and narrow lot, and past the point of renovation — the only use was to tear it down and rebuild. The client's real question was not whether the house was good but whether $8M for the land could be recovered on the far side of a rebuild. Marie Wang and Kevin Mo ran the numbers on the full rebuild, end to end. About 5,000 square feet with no basement: roughly $4M in construction, roughly $12M all in. With a basement and the finish level a $10M-plus house actually needs: roughly $6M in construction, roughly $14M all in, before carrying cost. Completion three years out, with an optimistic resale that might reach $21M to $22M. The conclusion split by purpose: as a build-to-sell investment it did not work at the asking price and would need to come down to roughly $7M to leave room; as a build-to-live-in it was roughly break-even at $8M. The wider old-house-versus-new-build math is worked through in a century-old Palo Alto house versus a new build.
What matters here is the phrase "completion three years out." Inside any three-year completion assumption, construction is only one segment; entitlement is counted in months too, and during those months capital is committed and producing nothing. A rebuild pro forma that counts only construction cost is missing a whole segment.
The second is Woodside. MK Group met with a family with a $35M budget who would look nowhere else, because the whole family rides and they needed stables, paddocks, and room to ride. Marie Wang and Kevin Mo raised Atherton as an alternative and the family declined outright — that full trade-off is set out in choosing a Woodside equestrian estate over Atherton. What makes it relevant here is that the lifestyle choice was also a regulatory choice. The first section of Woodside's design evaluation criteria lists four tests: rural character and community aesthetics, scenic corridors and vistas, the natural environment, and equestrian lifestyle — whether the project preserves and supports equestrian facilities and the Woodside trails network. You come to this town for the horses, and the board reviewing your drawings will weigh your project against horses and trails. Nowhere else among the seven does that appear in the code.
Common misconceptions
Misconception 1: "The more expensive the town, the stricter the approval."
It does not hold. Atherton is one of the most expensive ZIP codes in the country and has no standing design review board. Los Altos Hills says in its own documents that it does not run formal architectural review — a line that has to be read alongside another: every new residence in that town goes to a hearing. The two towns that do maintain standing design review bodies are Portola Valley and Woodside, neither of which sits at the top of the local price range. What shapes approval culture is what the town is trying to protect: valley views, rural character, trees, geologic safety.
Misconception 2: "It's a single-story addition, so there's no hearing."
Broadly true on conforming lots in Palo Alto and Menlo Park. Entirely false in Portola Valley, where the threshold is 400 square feet — one primary suite clears it. In Woodside you first check whether the lot is in a scenic corridor or the Western Hills, because location sets whether the threshold is 1,000 or 2,000 square feet. In Los Altos Hills a single-story addition can stay administrative, but anything that is a new residence goes to a hearing regardless.
Misconception 3: "Finish the design, then go ask the town."
This is the expensive one. In Atherton one protected tree can fence off a substantial patch of untouchable ground; discovering it after the drawings are done means redrawing them. In Woodside, slopes over 35 percent have to be subtracted from lot area before the Natural State requirement can even be calculated, and that takes a survey certified by a licensed engineer or surveyor. In Los Altos Hills a surveyor or civil engineer sets the story pole corners. In all three the correct order is the same: let the technical consultants draw the lot's hard boundaries, then let the architect design inside them.
Misconception 4: "Once it's approved I can build at my own pace."
Tolerance for delay varies widely. Woodside's code deems an application inactive once it has been incomplete for six months, or once a completed conceptual design review has gone six months without a formal application; the town then gives 60 days to cure, after which fees are refunded and the application is closed. Approvals lapse if no building permit issues within two years. Portola Valley's ASCC approval likewise expires if the permit has not issued within two years — and it does not even take effect until day sixteen, after a fifteen-day appeal period, which is when you may first apply for the building permit. Atherton goes further and writes completion deadlines into law with penalties for overrun. Buyers often treat approval as the finish line. It is the start of another clock.
Misconception 5: "Approval time doesn't affect me — I'm going to live in it."
Owner-occupants face no resale pressure, but carrying cost is paid either way: loan interest, temporary housing, contractor availability, material escalation. Every additional three months in entitlement is real cash out. The only difference is that an owner-occupant books it as cost of living and an investor books it as cost of capital.
Next steps
- Place the lot before you estimate the schedule — and do it before you write the offer. Confirm lot area, whether width and depth conform, average slope, whether the parcel sits in a scenic corridor or the Western Hills, and whether protected trees are present. Those parameters set your path, and the path sets the time.
- Confirm jurisdiction. A mailing address is not a permitting authority. West Menlo Park, Menlo Oaks, and similar county pockets permit through San Mateo County on a different process and a different clock. One phone call answers it, and getting it wrong costs months.
- Hire consultants in the order the town requires. Geotechnical first in Portola Valley, where new residences and additions over 500 square feet must clear the Town Geologist. A licensed surveyor or civil engineer first in Woodside and Los Altos Hills. An arborist first in Atherton. Get the order wrong and the drawings get redone.
- Put the approval window in your financial model. Estimate "close to groundbreak" and "groundbreak to move-in" separately rather than quoting one combined duration. The first is set almost entirely by the approval path — and by whether your builder has actually filed in that town before, which is the screen set out in choosing a builder above $10M.
- Start watching the clock the day you are approved. Put the expiration date of the design approval, the building permit filing deadline, and any statutory completion deadline directly into the general contract.