Does a shell building need a Title 24 report?

Yes, for the regulated work in its permit. A shell is a newly constructed building, and compliance covers the features in that permit application, usually the envelope. Lighting and HVAC are documented when they are designed.

What lighting power applies to space with no tenant yet?

On the prescriptive path, Section 140.6(c)2E limits an unleased tenant area in a new multitenant building to 0.4 watts per square foot. In a performance model with no lighting plans and no known occupancy, 0.40 W/ft² is used for both designs.

Can a shell be permitted as unconditioned?

Yes, and the envelope requirements then wait, but lighting, solar readiness and the large-space daylighting rule still apply. When a tenant adds heating or cooling, the space becomes newly conditioned space and the envelope must comply in full.

Is the first tenant fit-out new construction?

It can be, because a newly constructed building is one never used or occupied for any purpose. The CEC advises checking the building department's policy on first-generation tenant improvements before the design is fixed.

Title 24 for a Shell Building

A shell building is newly constructed, so the Energy Code applies to whatever its permit includes, which is usually the envelope. Lighting and HVAC that are not designed yet are held neutral in a performance model, an area with no tenant is limited to 0.4 watts per square foot of lighting, and the tenant permits document the rest.

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What the shell permit covers

Section 100.1 defines a newly constructed building as one that has never been used or occupied for any purpose, which describes a shell. The Energy Commission's nonresidential manual adds that compliance is submitted for the features covered in the permit application only. A core-and-shell permit carries the structure and envelope, sometimes base-building systems, and often leaves out the lighting and HVAC each tenant will choose. For a shell that will be conditioned, the report documents the envelope, prescriptively under Section 140.3 or by performance, on the NRCC certificate of compliance.

Systems that are not designed yet

The performance approach can be run on part of a building: envelope alone, mechanical alone, or envelope with mechanical, lighting or both. Indoor lighting can never be modelled on its own. What the permit leaves out is modelled the same way in the proposed and standard designs, so it earns no credit and carries no penalty. The manual draws the consequence: an envelope-only shell cannot trade envelope performance against mechanical or lighting systems that do not exist yet.

The placeholders are fixed. With mechanical excluded, the software generally assumes a minimum-efficiency HVAC system. With no lighting plans, it uses the Area Category value where the occupancy is known and 0.40 W/ft² where it is not. The prescriptive path has the same idea in Section 140.6(c)2E: where no tenant is identified for a multitenant area of a new building, its lighting is limited to 0.4 watts per square foot and it is classed as unleased tenant area.

Permitting the shell as unconditioned

An owner can leave conditioning out and permit the shell as unconditioned. The envelope requirements then wait, but the shell is not outside the code. Section 100.0(e)2C still applies lighting, solar readiness and the large-space daylighting rule of Section 140.3(c) to new unconditioned buildings. In climate zones 2 to 15, an enclosed space over 5,000 square feet under a roof, with ceilings above 15 feet, needs daylit zones covering at least 75 per cent of its floor. Exception 2 lets a building with unfinished interiors plan smaller or lower future spaces instead, but not for storage or factory occupancies. The detail is on skylights for large enclosed spaces.

The deferral comes due later. When a tenant adds heating or cooling, the space becomes newly conditioned space, which Section 100.1 treats as an addition, and the envelope must then comply in full. The CEC's guidance warns that a code update between shell and fit-out can make that harder, notes that many building departments ask the owner to sign an affidavit at the shell permit, and recommends showing envelope compliance when the envelope is built.

The first tenant's permit

The fit-out documents what the shell left out: lighting, HVAC, controls and any acceptance testing. Whether it is treated as new construction or as an alteration is for the building department to decide. The CEC's manual says that where it classifies a first-generation tenant improvement as newly constructed, every new-construction requirement applies, including controlled receptacles and circuit separation under Section 130.5, and tells applicants to check that policy. See alteration or new construction and tenant improvements.

Solar on a speculative building

Section 140.10 applies its PV and battery rules to newly constructed buildings of the listed types. Tables 140.10-A and 140.10-B put unleased tenant space in the same row as offices, so space without a named tenant still has capacity factors. In multitenant buildings, Exception 5 can leave out tenant spaces of 2,000 square feet or less that have their own HVAC and their own meter, and battery capacity is based only on tenant spaces over 5,000 square feet. The method is on commercial solar PV and battery requirements.