Seven Drawing Sets, One House: Which Set Is Your Bid Priced From?

The Rivera house is a fictional example. The people, the lot, and the numbers are made up, and the problems are the kind that turn up on real projects.

The drawings for the Riveras' house went through seven versions. That's not unusual for a custom home. But laying them out in order shows something people building for the first time don't always expect: "the drawings" isn't one thing. It's a series, and your bid is priced from one moment in it.

The seven sets

Here's how it went, in order:

Set	What changed
1. Preliminary	The first complete-looking set. The early budget was built from this one.
2. Permit set	Sixteen sheets, 36 windows on the schedule, a concrete patio out back, no mechanical specification at all.
3. Window revision	Changes to the window package.
4. Window revision 2	More window changes.
5. Deck plan	The concrete patio became a wood deck.
6. Recombined set	Eighteen sheets. 31 windows. The deck plan and floor framing added. A mechanical specification appeared for the first time: boiler, water heater, and the heating layout. Wall insulation changed.
7. Bearing wall change	A structural change on the second floor.

Each of those changes moves cost. Five fewer windows is a different window package. A wood deck isn't priced like a concrete patio. A mechanical system that didn't exist on the permit set suddenly has a specification behind it. If a bid was priced from set 2 and the house is built from set 6, those two numbers describe different houses.

The details that contradicted the elevations

There's a second problem in the Rivera drawings, and it's one I'd look for on any set.

Some of the construction details on the later sheets were carried over from a template used for a multifamily project. They call for vinyl lap siding, a particular composite trim, and plastic-coated wire closet shelving. They even refer to "Type A" and "Type B" units, which make no sense in a single-family house.

Meanwhile, the elevations call for wood lap siding, vertical accent siding, a corrugated metal wainscot, wood band boards, and a stone base. The cover sheet mentions the stone too.

So the same drawing set describes two different exteriors. One on the elevations, one in the details. A builder pricing from the elevations and a builder pricing from the details could both say they priced the drawings, and come back thousands of dollars apart. Neither would be wrong.

This happens because detail sheets get reused from project to project. It saves drafting time, and most of the time the reused details are fine. But they're worth reading against the elevations, sheet by sheet, before the set goes out to bid.

What to do with this

Put a date on every bid. Every bid should name the exact set it was priced from, by date or revision number. "Per plans" isn't enough when there are seven plans. What a complete custom home bid should include covers this.

Send one set to everyone. If you're getting more than one bid, every builder needs the same set, and any revision during bidding goes to all of them at once. How to get builder bids you can actually compare has the rest.

Ask for a revised price when the set changes. If the drawings change after you've signed, the change should come with a written price, up or down. Fewer windows can be a credit. A new mechanical system is almost certainly a cost. Neither should happen silently.

Read the details against the elevations. Or ask your architect to. You're looking for the same thing called out two different ways. When you find one, decide which is right, and put that in writing before bidding.

Know what the set doesn't show. A set can be current and still leave out finishes or systems. See Core and shell only for what that does to the bid.

Questions worth asking

• Which drawing set, by date or revision, is this bid priced from?
• Have there been revisions since, and has the price been updated for them?
• Where the details and the elevations disagree, which did you price?
• Is the mechanical system designed in this set, or carried as an allowance?
• How will changes to the drawings after signing be priced and approved?