Loft & basement conversions

Loft & basement conversion contractors insurance

Converting lofts and digging out basements means structural work on someone’s existing home — and that’s exactly what makes insurers nervous. Damage to the existing structure, underpinning, party-wall disputes and excavation all push these jobs into hard-to-place territory. Apex arranges cover for conversion specialists, including the structural and basement work others avoid.

Part of: Construction & contractor insurance at Apex

In short

Cover for loft and basement conversion contractors: public and employers’ liability including damage to the existing structure, contract works, plant, and the underpinning and excavation exposures on basement jobs.

Why conversions are hard to place

A conversion isn’t a clean new build on an empty plot — you’re cutting into a structure someone owns and often still lives in. The biggest exposure is damage to that existing building, which cheaper policies quietly exclude. Basements add underpinning, excavation and the risk of undermining neighbouring properties, and both trades bring party-wall obligations. Underwriters price all of that carefully, and many won’t touch basement work at all.

We place conversion contractors through underwriters who will engage with the structural detail. Where a client requires it, we can arrange joint-names or dual-insured cover so the homeowner is protected too.

What the insurance covers

Public and employers’ liability.
Damage to the existing structure you’re working on — the cover that matters most, and the one most often missing.
Contract works on the new works.
Plant, tools and temporary works including propping.
Joint-names / non-negligence cover where the client requires it.

Loft and basement work we place

Loft conversions and dormers
Roof structure alterations
Basement digs and floor lowering
Underpinning as part of a conversion
Light structural steel and beam installation
Extensions tied to a conversion

Cover and terms depend on the structural method and engineering sign-off. Deep basements and standalone underpinning are underwritten case by case — tell us the specifics and we’ll be straight about what can be placed.

What underwriters want to see

The structural engineer’s design and sign-off, any party-wall awards, your method for underpinning and excavation, whether the property is occupied, and how you monitor for movement. Having these ready is the difference between a decline and a workable quote.

Related construction cover

Construction hubAll contractor cover GroundworksExcavation and hard-to-place Joint names coverProtect the homeowner too Single projectOne-off contract works

Frequently asked

Is damage to the existing house covered?

It can be, and it’s the cover that matters most on a conversion. Budget policies often exclude the existing structure — we make sure yours doesn’t by accident.

Do you cover underpinning?

As part of a conversion, generally yes, subject to method and engineering sign-off. Standalone underpinning and piling in isolation are more restricted.

Basement digs?

Yes — priced on depth, method and the neighbouring structures. The more detail you give us, the better the terms.

Working on occupied homes?

Placeable. Underwriters simply want to know people are living there so they can rate it properly.

Party-wall damage?

We structure liability cover around the party-wall position — keep your awards and condition surveys, as they help both cover and any claim.

Cover for the structural jobs others won’t touch

Tell us the conversion, the method and whether it’s a basement, and we’ll arrange cover that reflects the real work. Or call 0117 325 0027.

Get a quote Call 0117 325 0027

Apex Insurance Brokers Limited is authorised and regulated by the Financial Conduct Authority. Registered in England and Wales, company number 07014570. This page is general information, not advice on your individual circumstances, and it does not guarantee that cover will be available or on what terms.