Architect Plans? How a Long Island Builder Prices Them

By Lior Golan, Founder & Principal, Prestige Custom Building & Construction. Last updated September 2026.

You hired an architect, you paid for the drawings, and now you need someone to build them. After “what will it cost?”, it’s the question I hear most from Long Island homeowners: I already have architect plans, will you price them? Whether a builder can give you a real number depends on what the set leaves open.

Custom homes built under contract for an owner, not for sale, make up 20% of U.S. single-family starts on a one-year average (NAHB, 2026). Here’s what a builder needs, what I check first, and who stays responsible for what.

Key Takeaways

• In New York, a building department approves construction documents only when they show the work conforms to the codes, including a site plan drawn from an accurate boundary survey (NY Department of State, 2022).

• A permit set isn’t automatically a construction set. The AIA notes that the level of detail in construction documents “may vary depending on the owner’s preference” (AIA, 2023).

• Interior finishes are the largest share of construction cost, 24.1% in NAHB’s 2024 survey (NAHB, 2025), so in my experience open items in the finish schedule leave the most to guesswork.

• Your architect’s seal means the architect is responsible for the design (NYSED Office of the Professions). The builder builds it, coordinates it and prices it.

What Does a Builder Need to Price Your Architect Plans?

A builder needs the same package your building department reviews, plus the documents that say what you actually want installed. In New York that starts with drawings showing the work conforms to code, a site plan drawn from an accurate boundary survey, and the structural, electrical, plumbing and mechanical systems (NY Department of State, 2022).

In practice, I ask for 5 things. If one is missing, I can still read the set, but I can’t give you a number I’d stand behind.

The survey matters more on the North Shore than people expect. On a waterfront lot in Sands Point or Lloyd Harbor, the state’s site plan rules can also call for flood hazard areas and design flood elevations. Still choosing the land? Our notes on choosing the right lot for a custom home help.

Is a Permit Set the Same as a Construction Set?

Not always. A permit set has one job: to show the building department that the work conforms to code. New York’s rule asks for information “sufficient to enable” the authority to make that call (NY Department of State, 2022). A construction set tells the people building your home exactly what to build.

The AIA describes construction documents as drawings that “typically include specifications for construction details and materials,” the set an architect sends to contractors for pricing or bidding (AIA, 2023). So two sets can both carry a seal and settle very different amounts. One proves the stair meets code. The other tells the millworker what to build.

So which one are you holding? If the flooring reads “owner’s choice” or the lighting plan shows symbols with no fixtures, it’s likely a permit set. That’s fine. A builder just has to price the decisions you haven’t made yet.

Our custom homes page compares permit-ready plans with construction-ready documents. For what the permit itself covers, see our guide to the Long Island custom home permit process.

What Does a Careful Builder Check Before Putting a Number on Your Plans?

Five things: whether the design can be built as drawn, where the specifications say nothing, which items are allowances instead of selections, what the site will add, and whether the engineering matches the architecture. Interior finishes alone were 24.1% of construction cost in NAHB’s 2024 survey, the largest share (NAHB, 2025), so the gaps matter.

Constructability

I read the set the way a framer, a mason and a plumber will. Does the steel fit in the floor depth shown? Is there room for the ductwork the house needs? When the answer isn’t clear, the question goes back to your architect in writing. It doesn’t get solved quietly on site.

Gaps in the specifications

A note like “tile per owner” isn’t a price. Each gap is a decision somebody makes later, at a later price. Plumbing, electrical and HVAC rough-ins were another 19.2% of construction cost in the same NAHB survey (NAHB, 2025), and a thin MEP design leaves much of that to guesswork. Facing a blank finish schedule? Start with choosing finishes for a modern luxury home.

Allowances versus specified items

An allowance is a placeholder number for something nobody has chosen yet. It makes two bids look comparable when they aren’t. One builder carries a modest tile allowance, another prices what your drawings imply, and the lower bid wins until the tile is picked. Before you sign, read what to ask a custom home builder about allowances.

Site conditions

Drawings show a house. The lot decides what it takes to put it there. Grades, fill, trees, drainage and truck access don’t live on the floor plan, so the survey and a site visit come before a number. Weighing a tear-down lot? See knockdown-rebuild on the Gold Coast.

Engineering coordination

The structural drawings, the MEP design and the architecture have to agree. When a beam in the engineer’s set doesn’t fit the ceiling height in the architect’s section, somebody has to pick one. My job is to find those conflicts on paper and send them back to the people who own them.

Want the questions to ask any builder before you sign? Our free custom home planning guide includes 12 of them and what moves the cost.

Who Is Responsible for the Design Once a Builder Is Involved?

Your architect is, even after a builder signs on. New York guidance says an architect’s seal and signature indicate “that a licensee is responsible for the work” (NYSED Office of the Professions). Engineers who seal the structural or MEP drawings take the same professional responsibility for theirs (NYSED Office of the Professions).

The builder’s job is different. I build what’s drawn, coordinate the trades and raise questions. When I find a conflict, I don’t redesign it. I send it to your architect in writing, and the answer comes back from the person who sealed the drawings. That keeps the design with your architect and keeps a record of every change.

State guidance says you’ll generally need a licensed design professional “any time you need the approval of a government agency or official for a construction project” (NYSED Office of the Professions). On projects that start with us instead, architecture is by our licensed architect partners, and our interior architecture page shows how we coordinate that work with the build. New to the vocabulary? Start with 5 architecture terms to learn before building.

How Is Pricing Set When You Bring Your Own Architect Plans?

I price your set by turning what it leaves open into decisions before the budget is set. Our new homes start from $1.5M, typically $400-500 per square foot, all-in, and where your plans land depends on what they specify and where they’re silent. Two homes of the same size can land far apart on finishes alone.

Where the plans leave finishes open, those selections are made before the budget is set, and your budget is set before construction begins. A number built on guesses only looks low until the guesses get made.

Renovation plans work the same way, with one more layer to read: the existing house. Our renovations start from $500K, typically $380-430 per square foot, all-in, and our home renovations page covers how we scope it.

When Does Design-Build Make More Sense Than Bringing Your Own Plans?

When the plans are early, over budget, or have never been priced against real selections. If you have concept drawings but no construction set, or the design grew past the number you’re comfortable with, design-build can help. Design and construction run as one process, with architecture by our licensed architect partners and construction by Prestige.

If you have a good architect and a complete set you love, keep them. A strong set should be built as drawn. Here’s how bringing your own plans compares with design-build:

Our design-build process walks through each step, and our guide on how to choose a custom home builder on Long Island compares design-build vs a general contractor with a separate architect. You can also see finished work, like the Brookville Cedar Estate.

Frequently Asked Questions

Will a builder price architect plans that are only a permit set?

Yes, but expect allowances wherever the set is silent. A permit set shows the building department the work conforms to code (NY Department of State, 2022). It doesn’t have to name your tile, fixtures or hardware. Ask every builder to list the allowances they carried, so you can compare bids on the same assumptions.

Do I need a new survey before a builder can price my plans?

Often, yes. New York requires the permit site plan to be drawn in accordance with an accurate boundary survey (NY Department of State, 2022). If your survey is old, or the lot has changed since it was done, ask your surveyor whether it needs an update before you ask builders for numbers.

Can a builder change my architect’s design?

Not on their own. An architect’s seal indicates the architect is responsible for the work (NYSED Office of the Professions). A careful builder flags conflicts and suggests alternatives in writing, and your architect decides whether to revise the drawings. That keeps responsibility with the architect who sealed them.

Why do bids on the same architect plans come in so far apart?

Usually because each builder filled the gaps differently. Interior finishes are the largest share of construction cost, 24.1% in NAHB’s 2024 survey (NAHB, 2025), and a set that leaves them open invites every bidder to guess. Compare allowances and exclusions line by line before you compare totals.

Does every home in New York need an architect’s seal on the plans?

No. New York’s licensing law, as NYSED explains, exempts residence buildings of 1,500 square feet or less, not counting garages, porches, cellars and similar areas (NYSED Office of the Professions). It also notes a community with stricter rules can require a seal for any construction, so check with your building department.

If you already have architect plans, you’re further along than most people who call me. If you’d like a builder’s read on your set, book a consultation and bring your drawings, your survey and any engineering you have. You’ll talk with me directly. I’ve spent 30+ years building on Long Island, with 100+ homes built and renovated, and we take on only 5-6 projects a year, so I’ll tell you plainly whether your plans and your budget line up.

Architectural and design services are provided by independently licensed architects. Prestige Custom Building & Construction, Inc. is a licensed home-improvement/construction company and is not a licensed architecture firm.

Lior Golan is the founder of Prestige Custom Building & Construction, a custom home builder serving Long Island’s Gold Coast and the Hamptons. Over more than 30 years he has guided over 100 custom homes and renovations across the North Shore, from Roslyn and Sands Point to Cold Spring Harbor.