BOQ for commercial and mixed-use buildings: shell, tenant fit-out and the separations that get forgotten
A BOQ for commercial and mixed-use buildings starts with a question that a residential bill of quantities never has to ask: what the developer hands over, and what the tenant does himself. The commercial shell and the tenant fit-out are two levels of handover within the same walls, and in a mixed-use building with retail and housing a third layer is added: the separation between the two uses. This page explains how such a bill is built, and where the usual mistakes are made.
The split that shapes the whole bill: shell versus tenant fit-out
The commercial shell is what the developer hands over: the structural frame, the building envelope, services up to the distribution board, public toilets, the facade and general fire safety. Tenant fit-out is what is done inside the unit: internal partitions, flooring, lighting, internal air conditioning and branding. In a BOQ for commercial and mixed-use buildings, every item is classified into one of the two groups. Without that column you cannot tell who pays for what, and you cannot split the bill between the shell contractor and the tenants' contractors. When the handover is fully fitted rather than a shell, the items are the same and the classification flips; the structure of the bill does not change.
The most expensive mistake in retail is unit flooring that appears both in the shell and in the tenant fit-out. The second is a shopfront that appears both in the metalwork schedule and in the aluminium schedule. The difference between a main contractor's bill and packages for subcontractors is explained on the bill of quantities page.
What sets retail apart from residential, item by item
| In residential | In retail |
|---|---|
| A protected room (mamad, the reinforced safe room in every Israeli flat), one for each flat | An institutional protected space on each floor, whose number derives from the floor area and not from the number of units |
| Doors and windows from the flat's schedule | A layout by the tenant's plan, display windows and a shopfront |
| Balconies and laundry screens | Roller shutters, wayfinding signs and branding |
| A water meter for each flat | A meter for each commercial unit, and separate electrical boards |
| Residential imposed load | A higher imposed load on the slabs, as set by the structural engineer |
| Fire detection by flat | Addressable fire detection and mechanical smoke extraction in enclosed areas |
A mamad on a retail floor is a mistake that gives away a copy from a residential template. Sprinklers are counted as the area divided by the coverage area per head, and the coverage per head depends on the hazard classification of the use; a fixed number without a classification is a defect in the bill. A grease separator and provisions for restaurants are recorded as missing when there is no tenant mix, not as zero.
BOQ for commercial and mixed-use buildings: four points that get forgotten
- Acoustic separation. A floating floor or an acoustic ceiling between the retail and the residential parts. The build-up is set by the acoustic report, not by assumption, and it is an item that is easy to forget because it does not appear in any residential template.
- Separate meters and boards. One electrical board for two uses is not a saving, it is a defect. A meter for each commercial unit, and a separate board for the residential part.
- Circulation cores. A separate entrance for the residents, or at least a separate lobby, a goods lift and an accessible lift. Each of them is an item.
- Area split. The sum of the retail and residential areas must equal the floor area. If it does not, one of the uses has been counted twice or has disappeared, and every ratio derived from the areas is affected.
The denominator in a mixed-use building. In my reasonableness checks, the denominator is set for each use on each floor separately, not for the building as a whole. A ratio of flooring per m² or of sprinklers per m² over a combined retail and residential area says nothing about either of them. More on such checks is on the quantity cross-check page.
The items that recur in a commercial bill
Concrete for retail slabs at the higher load, escalator openings in the slab that reduce the concrete pour and add formwork, separation walls between units and an acoustic wall between retail and residential, display windows and a shopfront with roller shutters, fittings for the floor's institutional protected space, public toilets, electrical provisions for the tenant up to the board, external plaster on the envelope by perimeter times height minus the display windows, air-conditioning provisions and condenser locations, acoustic ceilings in public areas, sprinklers and smoke extraction. A fire door appears in the metalwork chapter and also in the fire safety chapter; it is measured once, and the line says where.
Most of these items come from the consultants' bills: acoustics, electrical, HVAC, fire safety and lifts. In the contractor's bill they are consolidated as they are, without being reworded, and with a check that the areas and the number of floors in each consultant's bill match the structural drawings. Consolidation is covered on the consultants' bills of quantities page.
What a professional quantity surveyor adds here
Someone who measures only by what is marked gets a bill for one building, without knowing who pays for what. A quantity surveyor who comes from the field, an engineer or a registered building technician who worked on site, like Yaakov Avital, and who has priced retail tenders for a main contractor, classifies every item as shell or tenant fit-out, and checks the separations between the uses. For example, the architectural plan shows the retail floor with an ordinary slab, while the acoustic report requires a floating floor across the whole residential area above it. Measuring by the plan would leave out the floating floor; a professional check flags a question to the architect and the acoustic consultant, and they decide.
In a mixed-use building, the quantity takeoff has to separate the shell works from the tenant works. A quantity surveyor who marks that boundary on every line saves arguments, because the quantity takeoff shows who pays for what.
Frequently asked questions
What is the difference between a commercial shell and tenant fit-out?
The shell is what the developer hands over to all the tenants: structural frame, facade, services up to the board and public toilets. Tenant fit-out is the work inside the unit for the needs of a particular tenant. In the bill, every item belongs to one of the two.
Can a residential bill be used for a retail floor?
Not as it is. A flat's mamad, a flat's meter and a schedule of openings by flat do not exist in retail; in their place come an institutional protected space on each floor, meters per unit and a layout by the tenant's plan. The structure of the bill is similar; the content is different.
What is needed to write a bill for a mixed-use building?
Architectural and structural drawings with the area split by use, an acoustic report, a fire safety plan, and the consultants' bills for electrical, HVAC and lifts. Preparation is covered on the BOQ preparation page.
Who prepares the shell and tenant classification?
The classification is set with the developer according to the lease agreements, and it is recorded in the bill as a column. The work of a quantity surveyor for construction projects includes the classification, and the check that no item is counted in both groups.
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Contact me for a quote* Created with AI for marketing, for illustration only. Not reviewed by Yaakov Avital and not professional advice. Every project must be checked on its own by a professional quantity surveyor and an engineer.