A loft conversion turns unused roof space into a habitable room such as a bedroom, bathroom or office, with a proper staircase, insulation, fire protection and natural light from rooflights or a dormer.
For a homeowner in Brentwood, planning a loft conversion tends to begin with two questions: what will it cost, and how disruptive will it be? Our guide range is £31,500–£68,000 including VAT, and a typical job runs to 6–10 weeks on site. Both numbers firm up once we have seen the property, measured up and agreed exactly what is included.
- Guide price
- £31,500–£68,000 inc VAT
- Time on site
- 6–10 weeks on site
- Postcodes
- CM13, CM14 and CM15
- Planning rules
- England
- Local area
- Essex
- Survey
- Free, with a written quote
What should you budget for a loft conversion in Brentwood?
To help you plan, we show what a loft conversion typically costs in Brentwood instead of holding figures back for a sales call. The range is £31,500–£68,000 with VAT, using rates in the East of England that are about 5% above the national guide. A free survey then fixes your actual price.
| Type of job | What it usually involves | Guide in Brentwood |
|---|---|---|
| Rooflight conversion | Rooflights in the existing slope, a new floor, staircase and insulation, where head height already works. | £21,000–£37,000 |
| Dormer conversion | A rear dormer adding headroom and floor space, often with a bedroom and shower room. | £33,500–£63,000 |
| Hip-to-gable or mansard | Larger structural changes to the roof for the maximum usable space. | £52,000–£89,000 |
The main things that change the figure:
- Floor area, existing head height and roof structure
- Steelwork and any strengthening of walls below
- Adding a shower room or en-suite in the roof
- Staircase layout, fire doors and the level of finishes
What does the job include in Brentwood?
- Structural calculations and steel beams where needed
- New floor joists strong enough for a habitable room
- Staircase designed to fit your landing and meet regulations
- Insulation to walls, roof slope and floor
- Fire doors, mains-linked smoke alarms and a protected escape route
- Electrics, heating and plumbing by qualified trades, with certificates
Building in Brentwood
Essex ranges from timber-framed and weatherboarded cottages in the north, some with decorative pargeting, to Victorian terraces in Colchester, Chelmsford and Southend. Basildon and Harlow were built as post-war new towns, much of the south-east has interwar suburbs and bungalows, and large new estates continue to appear around Chelmsford and Braintree.
Terraces and semis commonly suit loft conversions and rear extensions, and many bungalows can take a loft room. New-town homes often need cladding, window and roofline renewal, while timber-framed cottages call for lime plaster and repairs that respect the original frame.
That variety is why a guide price for a loft conversion in Brentwood is only a starting point; the survey shows what your particular property needs.
Permissions for a loft conversion in Brentwood
Homes in Brentwood come under the regulations for England, summarised below. We don't rely on general rules alone: we confirm the position for your address with the council before a quote goes out.
In England, many loft conversions are permitted development: up to 40 m³ of extra roof space on a terraced house and 50 m³ on a semi-detached or detached house, no dormer on the front roof slope facing a road, nothing higher than the existing roof, and similar-looking materials. Conservation areas, listed buildings and flats need planning permission.
Building Regulations approval is always needed for a loft conversion: floor strength, a proper staircase, insulation, fire-protected escape route and smoke alarms. The Party Wall etc. Act 1996 usually applies on attached houses.
Rules change and every property is different, so we check the planning history and constraints for your address before we quote.
How does the job run?
A visit to your home
A free survey comes first. It gives us what we need to price a loft conversion properly, including dimensions, existing materials and access for deliveries, and gives you the chance to ask anything you like.
Your fixed price
We put everything into a written, fixed-price quote: the specification, what's excluded, staged payments and the expected time on site. Take whatever time you need to decide; there's no pressure to commit.
Dates and permissions
We handle the paperwork side: checking whether planning permission or building control approval is needed, submitting applications where they are, and scheduling the trades and materials around your dates.
On site to finish
During the work we protect the areas around it and tidy up at the end of each day. Once complete, we check the finish, remove our materials and hand over paperwork such as building control sign-off where it applies.
Why homeowners choose us
Common questions
Do you cover Billericay, Hornchurch and Romford?
Yes. As well as Brentwood, we cover Billericay, Hornchurch and Romford and the rest of Essex. Our coverage is UK-wide, so the process is the same wherever you are: a free site survey, a quote in writing that fixes the price for the agreed scope, and one point of contact while the work is planned and carried out.
What fire safety measures does a loft conversion need?
A loft conversion needs a safe way out in a fire, because the new room is high above the ground. This usually means a protected stair route down to an exit, with fire doors onto the stairway, mains-linked smoke alarms on each floor and sometimes an escape window. The exact approach depends on your house layout. Building control checks these measures before signing off the work.
How much does a loft conversion cost?
A typical dormer loft conversion on a 3-bed semi costs £31,500–£68,000. A simple rooflight conversion costs less, while hip-to-gable and mansard conversions cost more because they change the roof structure. As a rough guide, allow around £800–£1,700 per square metre of new floor plus fixed costs for the staircase, steels and fees. Adding a shower room is the most common extra. We confirm a fixed price after surveying your loft.
Is my loft suitable for conversion?
A loft is usually suitable for conversion if there is enough head height, a roof structure that can be adapted and space for a staircase. A common rule of thumb is at least 2.2m from the top of the ceiling joists to the underside of the ridge, though dormers and mansards can create height where it is short. Modern trussed roofs need more structural work. We check all of this at the survey.
Can I stay at home during the work?
In most cases, yes. Most people can live at home throughout, and we plan the work to keep disruption down by protecting floors, agreeing working hours and keeping access routes clear. Bigger jobs affecting kitchens, bathrooms or heating may mean a short spell with reduced facilities, and we talk this through with you at the survey.
Nearby towns
We welcome enquiries from all CM13, CM14 and CM15 postcodes in Brentwood, plus Billericay, Hornchurch and Romford. Each one gets the same survey at no charge and a written price fixed for the work described.