"Core and Shell Only": When Your Drawings Don't Include Finishes

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.

On the cover sheet of the Riveras' drawings, there's a general note that's easy to read past. It says, more or less: these drawings are core and shell only, and finishes and fixtures shown are for location only.

That one sentence decides how the whole house gets priced. And a lot of people building custom homes have the same note on their drawings without knowing it's there.

What the note means

"Core and shell" means the drawings describe the structure and the envelope: foundation, framing, roof, walls, windows, and the major systems if they're designed. They show where the kitchen goes, where the tub goes, and where the vanity sits. They don't say what any of those things are.

"For location only" means that the toilet drawn in the bathroom is telling the plumber where to put the drain, not which toilet to buy. The pendant drawn over the island marks a junction box. The tile hatch on the shower wall shows where tile goes, not what tile.

That's a completely normal way to draw a house. Architects aren't always hired to select finishes, and a lot of people want to choose those things themselves, later, with the builder or a designer. There's nothing wrong with it. You just need to know what it does to the bid.

Where to find it

Look at the general notes, usually on the cover sheet or the first sheet of the set. Search for phrases like "for location only," "for reference only," "by others," "core and shell," or "by client." Also check the sheet index for a finish schedule, a room finish schedule, or a fixture schedule. If there isn't one, that tells you the same thing.

On the Rivera drawings, the note is there and the finish schedule isn't. So the drawings say nothing about tile, flooring, cabinets, counters, plumbing fixtures, lighting, trim, or doors.

What it pushes into the bid

If the drawings don't describe finishes, a builder can't price them from the drawings. Everything a finish schedule would have covered moves into allowances: a dollar amount for each category, standing in for a decision nobody has made yet.

The Riveras' early budget carries allowance-type lines for appliances, cabinets, countertops, tile, wood flooring, carpet, interior doors, hardware, mirrors and shower doors, the fireplace, and even windows and garage doors. Taken together, that's a big share of the house. Every one of those numbers is a guess about something the drawings don't describe.

That's the real effect of the note. A bid on core-and-shell drawings can be detailed and accurate about the structure and still leave a large part of the final cost sitting in placeholders. If those placeholders are set low, the bid looks better than the house you'll actually build. Allowance math shows how fast that adds up.

What to do about it

You don't need to hire someone to draw a full finish schedule, though it helps if you can. What you need is enough written down that every builder is guessing at the same house.

Start with a one-page finish brief, room by room: the kind of flooring, cabinet construction, counter material, tile and how high it goes, plumbing fixture level, lighting approach, and trim. Product types are enough. Closing the gap between what you picture and what your builder priced walks through how.

Then set the allowance amounts yourself and send them to every builder, so the allowances can't make one bid look cheaper than another. How to get builder bids you can actually compare covers that.

And when the bids come back, read the allowance list as carefully as the rest. With core-and-shell drawings, it may be the most important page.

Questions worth asking

• Do my drawings include a finish schedule, or a note that finishes are for location only?
• Which categories in the bid are allowances because the drawings don't describe them?
• What does each allowance assume, in product type and quantity?
• Is each allowance material only, or installed?
• If I give you a finish brief, will you price from it and update the allowances?