Banquette & Built-In Seating Shop Drawings: Structure, Upholstery, and Storage

Built-in seating is one of the few millwork categories where the drawings have to serve two separate fabricators simultaneously: the millwork shop building the wood frame, and the upholstery shop covering it. If the shop drawing only shows the finished upholstered dimensions without the structural frame dimensions — or only the frame without the finished size — one of those two trades is guessing, and the finished seating won't sit at the right height.

I've seen banquette projects come back for field adjustment because the seat height was specified as a finished dimension but built as a frame dimension, adding 2" of foam on top of an already-high structure. In a restaurant where seating height is coordinated with table height, that's a functional problem, not just an aesthetic one. Our millwork shop drawing services always show both structural and finished dimensions on banquette packages — and document the upholstery allowances explicitly so both trades are working from the same numbers.

Standard Banquette Dimensions: What to Design From

Before drawing anything, establish the target finished dimensions. For a standard restaurant banquette coordinated with a 30" dining table:

These finished dimensions then drive the structural frame dimensions after deducting the upholstery allowance.

Upholstery Allowances: The Critical Deduction

The structural wood frame must be undersized to account for the foam, batting, and fabric layers that will be applied by the upholstery subcontractor. Standard allowances:

• Seat cushion (plush foam + fabric): deduct 2"–3" from finished seat height for the frame top panel height. A 17" finished seat height with a standard cushion build = 14"–15" frame top panel height
• Seat cushion depth: deduct 1"–2" from finished seat depth for the frame back panel and cushion overhang
• Back cushion (if upholstered): deduct 2"–4" from finished back depth for the back frame. Button tufting adds depth — a tufted back may require a 4" deduction vs. a 2" deduction for a flat cushion back
• Inside corner radius: the inside corner of the banquette back frame should have a 2" minimum radius if the back cushion wraps the corner — a sharp inside corner creates a crease in the fabric that looks wrong and stresses the material at that point

Both sets of dimensions — structural frame and finished upholstered — must appear on the drawing, clearly labeled. "Frame dim." and "Finished dim." annotations at each critical measurement eliminate ambiguity.

Structural Frame Construction

Banquette frames are structural — they're sat on repeatedly and must support occupant loads without racking or loosening over time. The drawing must specify:

• Plywood grade: 3/4" A/B for structural panels; A-face oriented toward any visible surface. Specify "cabinet-grade, void-free" if budget allows — voids in the plywood core create soft spots under upholstery
• Frame joinery: dado and rabbet joints with pocket screws or biscuits are standard; the drawing should note the joint type at major structural connections (seat rail to side panel, back frame to seat frame)
• Seat support: the seat deck (the plywood panel the foam sits on) must be supported from below — either with a full plywood base or with intermediate cross-supports at 16"–24" o.c. The drawing must show the support structure in section
• Wall attachment: in most installations, the banquette back attaches to the wall for stability; show the cleat or ledger detail and note the wall blocking requirement
• Blocking at wall: require a 2×6 or 2×8 blocking note in the structural wall behind the banquette attachment point — this must be installed before drywall and before the banquette is set

Storage Integration: Lift-Top vs. Front Drawers

Many residential and some hospitality banquettes include storage in the base. The drawing must show which storage system is used and how it's built:

Lift-top seat (piano hinge or gas strut). The seat deck is hinged at the back and lifts to reveal the storage cavity. Piano hinges are inexpensive and durable. Gas struts (lift supports) hold the lid open without requiring a second person to hold it — preferred in residential and hospitality. The drawing must show: hinge location and type, gas strut placement (typically 2 per seat section), and the clear storage height inside the base (must account for any intermediate supports below the seat deck).

Front-opening drawers. Drawers built into the base panel face beneath the seat. Requires enough base height for the drawer box plus the drawer slide (typically 8"–10" clear minimum). Shows on the drawing as a drawer elevation on the front face, plus a section showing the slide mounting and frame structure that allows the drawer to open.

Corner Conditions: Inside Corners and Returns

L-shaped or U-shaped banquette configurations create inside corners that require specific detailing:

Inside corner platform. A fixed diagonal, triangular, or square platform piece fills the inside corner. Seat cushions from each run terminate at the platform, with a separate corner cushion placed on top. The drawing must show the platform structure in plan view, the table clearance in the corner (a round or oval table is usually required here), and how the back panels from the two runs meet at the corner.

Mitered back panels. If the banquette back height extends to a wall shelf or wainscoting height, the back panels at the inside corner must be mitered. Show the miter angle and the backing block that ties the two panels together at the inside corner.

For full details on how restaurant and hospitality millwork submittals work, see our article on restaurant and bar millwork shop drawings.

ADA Positions in Commercial Banquette Seating

ADA-accessible seating in restaurants and hospitality is required at a percentage of total seating. Built-in banquette seating can be ADA compliant if:

• Seat height falls within 17"–19" AFF (standard banquette height typically meets this)
• A 30"×48" clear floor space is provided at the accessible position — this means the table must be positioned to allow wheelchair approach, which affects the table layout plan
• The table at the accessible position is at 28"–34" AFF (standard 30" tables comply)
• Knee clearance of 27"H × 30"W × 19"D minimum exists under the table at the accessible position

The shop drawing must identify the ADA-accessible positions on the floor plan and show the accessible dimensions at those locations.

Check our millwork drawing rates for hospitality and restaurant seating packages, and see our ADA compliance in millwork drawings guide for the full accessibility documentation requirements.

Frequently Asked Questions