What to send your contractor

This is the complete list a contractor would ideally see. Missing items are not a barrier to getting started — they simply mean the early quote will carry more assumptions until they are available.

Every item on the checklist removes a specific assumption from the quote and, later, from the build itself.

It helps to see the checklist as a set of specific questions a contractor otherwise has to guess the answer to. Working through why each item matters makes it easier to prioritise what to chase first if not everything exists yet.

Without drawings, a contractor is pricing floor area and rough guesswork against typical build-ups — a reasonable starting point for a conversation, but not a number to plan a budget around. Every missing item forces an assumption: an assumed foundation depth where no ground information exists, an assumed access route where no photographs have been sent, an assumed drainage strategy where none has been designed. Assumptions are not wrong on purpose, but they are a source of later variation whenever reality turns out to differ from the assumption made at pricing stage.

This is why two contractors quoting from the same thin brief can produce very different numbers — not because one is more expensive, but because they made different assumptions to fill the same gaps.

It is normal for early-stage projects to be missing most of this list. A site visit and a conversation with SHS usually establishes, in that case, what still needs commissioning and from whom — a topographic survey, a structural engineer, a percolation test, or a drainage designer, depending on the project. Sending what you already have is still worthwhile at that stage: it shapes the conversation and avoids repeating information later.

Not everything needs commissioning at once, and getting the order right saves money. A topographic survey generally comes first, because levels affect almost every other decision. A structural engineer usually needs that survey, plus architect's drawings, before producing calculations. Drainage design and a percolation test can often run in parallel with structural work. Ground investigation is worth commissioning early on any site where conditions are uncertain, because a redesigned foundation after other work has been done is the most expensive kind of change to make.

The quickest way to get all of this in front of SHS in one place is the Send Us Your Plans upload page, where drawings, photographs and documents can be submitted together with a short description of the project. There is no need to wait until the checklist is complete — sending what exists now, and flagging what is still outstanding, is enough to start a proper conversation grounded in real information rather than a floor area alone.

SHS is the contractor, not the planning authority. What SHS can do is look at the information you already hold from a build point of view — access, ground conditions, levels, drainage, foundations and buildability — and tell you plainly what the construction side is likely to involve.

If drawings already exist, send them. If they do not, a site visit and a conversation usually establishes what information you need to gather next and who you need it from.