Loft Conversions in Hertfordshire
Planning a loft conversion in Hertfordshire? We handle the design side — plans, structural calculations and planning applications — for homeowners across St Albans, Welwyn Garden City, Hertford, Hitchin, Stevenage, Watford and the rest of the county. Fixed-price package, no hidden fees, drawings in your inbox within 7 days.
- All of Hertfordshire covered
- Conservation area experience (St Albans, Hertford, Harpenden)
- Survey within 3 days (subject to access)
- Structural calculations included
- Planning & building control handled
- Fixed-price — no hidden fees
Conservation areas — read this before you commission drawings
Large parts of central St Albans, Hitchin old town, Hertford, Harpenden High Street and Berkhamsted sit inside designated conservation areas — and Permitted Development rights are restricted inside them. That means a full householder planning application is required even for a rear dormer. We check this for free before any drawings start and handle the submission, design & access statement and officer queries on your behalf.
Why Hertfordshire homeowners choose Loft Plans
What's included in our fixed-price package
Everything you need to hand a complete, build-ready pack to your builder — no surprise add-ons.
- Measured survey of your property
- Existing floor plans, sections & elevations
- Proposed floor plans, sections & elevations
- Structural calculations by a chartered engineer
- Planning application submission (if required)
- Building control drawings & specification
- Planning officer queries handled
- Unlimited revisions until you're happy
Featured project — L-shape dormer, Hitchin
A recent Hertfordshire project we designed: master bedroom, large ensuite with freestanding bath and walk-in shower, and an office space in the front eaves. We produced the architectural drawings, structural calculations and planning application, and recommended a trusted local builder to carry out the construction.
“Loft Plans handled all of the architectural drawings, structural calculations and the planning side for our L-shape dormer. They also recommended a local builder who carried out the construction to a good standard.”
Loft conversions across Hertfordshire
Hertfordshire has one of the most varied housing stocks in the South East — and almost all of it converts well. Victorian and Edwardian terraces in Hertford, St Albans and Hitchin are tailor-made for L-shape dormers that use the original rear outrigger. The 1930s semis that dominate Welwyn Hatfield, Watford, Borehamwood and Potters Bar are ideal candidates for hip-to-gable conversions, often combined with a rear dormer. Newer detached homes in Bishop's Stortford and Hemel Hempstead frequently have generous truss roofs that lend themselves to full rear dormers with double bedrooms and ensuites. We survey your roof, talk through what your family actually needs the space for, and design a layout that makes the most of the head height you've got.
Which conversion suits your Hertfordshire home?
| Conversion type | Typical build cost | Build timeline | Planning |
|---|---|---|---|
| Velux (rooflight) | £25,000–£30,000 | 4–6 weeks | Almost always Permitted Development |
| Dormer | £40,000–£45,000 | 6–8 weeks | Usually Permitted Development |
| Hip-to-gable | £45,000–£55,000 | 8–10 weeks | Usually Permitted Development |
| L-shape dormer | £45,000–£55,000 | 8–10 weeks | Often Permitted Development |
Build costs are indicative guides only — actual figures depend on size, spec and location.
Not sure which conversion suits your loft?
Get in touch — we'll measure up and tell you honestly what your roof can deliver.
Get in touchWorking with Hertfordshire planning authorities
Hertfordshire is split across ten district and borough councils — East Herts, Welwyn Hatfield, St Albans, Broxbourne, Hertsmere, Three Rivers, Watford, Dacorum, Stevenage and North Herts. Each runs its own local plan, householder design guide and validation checklist, and we deal with all of them regularly. The quirk that catches most homeowners out is conservation areas. Large parts of central St Albans, Hertford old town, Harpenden's High Street, Berkhamsted and the historic centre of Hitchin sit inside designated conservation areas — and in those zones Permitted Development rights are restricted, so a full householder planning application is needed even for a rear dormer. We check this for you before drawings start and handle the submission, drawings, design and access statement, and any officer queries on your behalf.
Hertfordshire areas we cover
We design loft conversions right across the county. A few of the towns and villages we work in regularly:
Frequently asked questions
Which areas of Hertfordshire do you cover?
All of Hertfordshire — including St Albans, Welwyn Garden City, Hatfield, Hertford, Ware, Hoddesdon, Cheshunt, Bishop's Stortford, Sawbridgeworth, Stevenage, Hitchin, Letchworth, Harpenden, Watford, Hemel Hempstead, Berkhamsted, Tring, Rickmansworth, Borehamwood, Potters Bar and Barnet.
Do I need planning permission for a Hertfordshire loft conversion?
Most rear dormer and hip-to-gable conversions fall under Permitted Development. However, large parts of St Albans, Hertford, Harpenden and Berkhamsted sit inside conservation areas where Permitted Development rights are restricted and a full planning application is required. We assess this on the survey and advise before any work starts.
How long do Hertfordshire plans take?
Survey within 3 days of getting in touch, draft plans within 7 days, structural calculations shortly after. If planning permission is needed, councils across Hertfordshire typically determine applications within 8 weeks of validation.
Which Hertfordshire councils do you work with?
East Herts, Welwyn Hatfield, St Albans City & District, Broxbourne, Hertsmere, Three Rivers, Watford, Dacorum, Stevenage and North Herts. We know each council's local plan, validation requirements and householder design guides — and submit applications directly via the Planning Portal.
What types of Hertfordshire houses suit a loft conversion?
Almost all of them. The county's 1930s semis (extremely common in Welwyn Hatfield, Watford and Borehamwood) suit hip-to-gable conversions. Victorian and Edwardian terraces in Hertford, St Albans and Hitchin are ideal for L-shape dormers using the rear outrigger. Bungalows across the county convert beautifully with a full rear dormer.
Have you completed loft conversions in Hertfordshire before?
Yes — extensively. The featured project on this page is an L-shape dormer in Hitchin: master bedroom, large ensuite with freestanding bath and walk-in shower, plus an office in the eaves. We produced the architectural drawings, structural calculations and planning application, and recommended a trusted local builder to carry out the construction.
Get a free quote for your Hertfordshire loft
Tell us a bit about your property and we'll come back with a fixed price and timeline.
Explore other conversion types
Ideal for the Victorian and Edwardian terraces common across Herts.
Perfect for the 1930s semis in Welwyn Hatfield, Watford and Borehamwood.
Maximum head height and floor area on most Herts roofs.
Lowest-cost option — usually permitted development.
Ready to start your loft conversion?
Get in touch and receive your first draft drawings within 7 days.
Get in touch