Updated 22 October 2026 · 84 new leads in the last 30 days
Construction Leads in Welwyn Hatfield
Access construction leads in Welwyn Hatfield by tracking newly submitted planning applications. See which homeowners and developers across Welwyn Garden City and Hatfield are preparing extensions, loft conversions, and new builds, and get in touch before they begin shortlisting builders.
- New planning applications added frequently from Welwyn Hatfield Borough Council
- Connect with homeowners at the early planning stage
- No shared enquiries or competitive bidding
Data sourced from Welwyn Hatfield Borough Council planning records and refreshed regularly.
84
New Leads (30 Days)
£131,703
Average Project Value
20
High Value Projects
Over £100k
Extensions
Most Common Project
Construction Trends in Welwyn Hatfield
Welwyn Garden City, founded in 1920 as Ebenezer Howard's second garden city after Letchworth, gives the borough a distinctive planned layout centred on the Howard Centre, with wide tree-lined avenues and a housing stock that continues to generate a steady flow of extensions and loft conversions. Hatfield, the borough's other main town, has a very different history rooted in aviation manufacturing — the former de Havilland aerodrome and factory, where the Comet airliner was built, has since been redeveloped as the University of Hertfordshire's de Havilland campus and Hatfield Business Park, bringing a mix of institutional and commercial construction activity alongside the town's residential streets. Away from the two main towns, the borough's villages keep a more rural character, generating smaller-scale extension and outbuilding work.
Project Type Breakdown
Here's a breakdown of the most common types of construction projects in Welwyn Hatfield over the past 30 days.
In Welwyn Hatfield, Extensions are the most common project type, appearing in 41 of the 84 leads tracked in the last 30 days, with Heritages also showing consistent demand alongside Garden Rooms. Projects can fall into more than one category, so these figures don't need to add up to the total.
Most Active Architects and Planning Consultants in Welwyn Hatfield
The architects and planning consultants submitting the most construction-related applications in Welwyn Hatfield, based on recent planning records.
- 1HOME EXTENSION DESIGNS LTD
- 2Keegans Ltd
- 3A.T. Design (Welwyn) Ltd
- 4Iceni Projects
- 5L Architects
- 6Dimensions- Planning&Architecture
- 7Paul Dickinson and Associates
- 8Principlanning
- 9Damien Poulter
- 10Nigel Cox Architects
Project Value Insights
Understanding typical project values in Welwyn Hatfield helps you prioritise the most profitable leads and manage your workload effectively. These ranges are a general guide to the scale of work involved — individual project costs vary by design, specification, and site conditions.
- £25k – £50kSmall extensions, porches, and internal alterations
- £50k – £100kRear extensions and loft conversions
- £100k – £250kLarge extensions and full property refurbishments
- £250k+New builds and high-end residential projects
Higher-value projects are often found in Welwyn Garden City’s established avenues, where larger period properties support more extensive upgrades.
Recent Planning Applications in Welwyn Hatfield
Extensions
| Project Type | Area | Est. Value | Description | Status |
|---|---|---|---|---|
| Rear Extension | Unit 3 Woodside Lane Hatfield AL9 6DE | £50k–£100k | Retention of an extension and erection of a rear extension following demolition of existing buildings. | Approved |
| Wrap-Around Extension | 47 Dixons Hill Close Welham Green Hatfield AL9 7EF | £50k–£100k | Erection of a single storey rear and side extension after demolishing an existing shed and W.C. | Approved |
| Side Extension | 6 Highfields Cuffley Potters Bar EN6 4EL | £100k–£250k | Conversion of garage to study, side extensions, and rooflight installation. | Approved |
| Single Storey Rear Extension | 1 Newstead Hatfield AL10 9DH | £50k–£100k | Prior approval for a single-storey rear extension 6.00m deep (eaves 2.60m, max height 3.00m). | Approved |
| Rear Extension | Welwyn Hatfield | £100k–£250k | Proposed ground and first floor rear extension to the dwelling. | Approved |
Rear Extension
Unit 3 Woodside Lane Hatfield AL9 6DE
Retention of an extension and erection of a rear extension following demolition of existing buildings.
Wrap-Around Extension
47 Dixons Hill Close Welham Green Hatfield AL9 7EF
Erection of a single storey rear and side extension after demolishing an existing shed and W.C.
Side Extension
6 Highfields Cuffley Potters Bar EN6 4EL
Conversion of garage to study, side extensions, and rooflight installation.
Single Storey Rear Extension
1 Newstead Hatfield AL10 9DH
Prior approval for a single-storey rear extension 6.00m deep (eaves 2.60m, max height 3.00m).
Rear Extension
Welwyn Hatfield
Proposed ground and first floor rear extension to the dwelling.
Loft Conversions
| Project Type | Area | Est. Value | Description | Status |
|---|---|---|---|---|
| Loft Conversion | The Beeches Leggatts Park Great North Road Little Heath Potters Bar EN6 1NZ | £250k–£1m | Single-storey rear extension, subterranean basement with vehicle access lift, and conversion of garage loft into a habitable room. | Approved |
| Loft Conversion | 33 Roe Green Lane Hatfield AL10 0SH | £100k–£250k | Part two-storey, part single-storey rear and side extensions, single-storey front extension, roof alterations including rear dormers and front rooflights, and demolition of detached garage. | Refused |
| Loft Conversion | 18 Briary Wood Lane Welwyn AL6 0TF | £100k–£250k | Single-storey ground floor extension, part two-storey rear extension, roof raised and loft conversion with new crown roof and front and rear dormers. | Approved |
| Loft Conversion | 36 Warren Way Digswell Welwyn AL6 0DN | £100k–£250k | Two-storey side extension, part single/two-storey rear extension, two front dormers and front porch following demolition of existing rear extension and detached garage. | Approved |
| Loft Conversion | Welwyn Hatfield | £50k–£100k | Proposed porticos to front and side entrances, new dormer windows, new/repositioned rooflights and alterations to rear windows. | Pending |
Loft Conversion
The Beeches Leggatts Park Great North Road Little Heath Potters Bar EN6 1NZ
Single-storey rear extension, subterranean basement with vehicle access lift, and conversion of garage loft into a habitable room.
Loft Conversion
33 Roe Green Lane Hatfield AL10 0SH
Part two-storey, part single-storey rear and side extensions, single-storey front extension, roof alterations including rear dormers and front rooflights, and demolition of detached garage.
Loft Conversion
18 Briary Wood Lane Welwyn AL6 0TF
Single-storey ground floor extension, part two-storey rear extension, roof raised and loft conversion with new crown roof and front and rear dormers.
Loft Conversion
36 Warren Way Digswell Welwyn AL6 0DN
Two-storey side extension, part single/two-storey rear extension, two front dormers and front porch following demolition of existing rear extension and detached garage.
Loft Conversion
Welwyn Hatfield
Proposed porticos to front and side entrances, new dormer windows, new/repositioned rooflights and alterations to rear windows.
Other Projects
| Project Type | Area | Est. Value | Description | Status |
|---|---|---|---|---|
| Dropped Kerb | Land north of The Meadway Cuffley Potters Bar EN6 4ET | Submission of details pursuant to multiple conditions (contamination verification, external lighting, SUDs maintenance, vehicle access, parking allocation, accessible homes) on permission 6/2024/0105/MAJ. | Refused | |
| Garden Room | Welwyn Hatfield | £25k–£50k | Replace existing shed with a garden office/workshop (outbuilding) in the rear garden. | Approved |
| Heritage | 1-13 Holwell Court Hatfield AL9 5RL | Installation of full-fibre broadband network to the building. | Approved | |
| New Build | 53 Brookmans Avenue Brookmans Park AL9 7QG | £250k–£1m | Demolish existing property and erect a replacement dwelling with boundary wall and gates. | Approved |
| Garden Room | 16 Oak Road Woolmer Green SG3 6LS | £50k–£100k | Erection of an annexe within the residential curtilage. | Approved |
Dropped Kerb
Land north of The Meadway Cuffley Potters Bar EN6 4ET
Submission of details pursuant to multiple conditions (contamination verification, external lighting, SUDs maintenance, vehicle access, parking allocation, accessible homes) on permission 6/2024/0105/MAJ.
Garden Room
Welwyn Hatfield
Replace existing shed with a garden office/workshop (outbuilding) in the rear garden.
Heritage
1-13 Holwell Court Hatfield AL9 5RL
Installation of full-fibre broadband network to the building.
New Build
53 Brookmans Avenue Brookmans Park AL9 7QG
Demolish existing property and erect a replacement dwelling with boundary wall and gates.
Garden Room
16 Oak Road Woolmer Green SG3 6LS
Erection of an annexe within the residential curtilage.
Data sourced from Welwyn Hatfield Borough Council planning records and refreshed regularly.
Featured Projects
A snapshot of recent construction opportunities across Welwyn Hatfield.
Retention of an extension to the existing building and the erection of a rear extension following demolition of existing buildings (part retrospective)
£50k–£100kUnit 3 Woodside Lane Hatfield AL9 6DE
Retention of an extension and erection of a rear extension following demolition of existing buildings.
Erection of a single storey rear extension and a single storey side extension following the demolition of an existing detached shed and an attached W.C.
£50k–£100k47 Dixons Hill Close Welham Green Hatfield AL9 7EF
Erection of a single storey rear and side extension after demolishing an existing shed and W.C.
Conversion of garage into study room with alterations to the front elevation, repositioning of lower ground floor entrance hall, erection of two storey infill side extension with internal alterations, replacement of existing front and side building brickwork with K-Render finish, removal of chimney and installation of 2 rooflights
£100k–£250k6 Highfields Cuffley Potters Bar EN6 4EL
Conversion of garage to study, side extensions, and rooflight installation.
Prior approval for a single storey rear extension measuring 6.00m in depth, 2.60m to the eaves and the maximum height of 3.00m
£50k–£100k1 Newstead Hatfield AL10 9DH
Prior approval for a single-storey rear extension 6.00m deep (eaves 2.60m, max height 3.00m).
Examples of projects at an early stage before wider competition builds.
See All 84 Construction Leads in Welwyn Hatfield
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Get Access NowPlanning Application Status in Welwyn Hatfield
42%
Approved
49%
Pending
9%
Refused
In Welwyn Hatfield, 42% of planning applications are approved, 49% are still pending, and 9% are refused. Pending applications can give builders an opportunity to make contact while projects are still at an early stage.
Earlier contact usually means less competition.
Based on planning applications submitted over the last 30 days.
Planning Approval Times in Welwyn Hatfield
Among applications tracked by BuildAlert in Welwyn Hatfield, the median time from submission to decision is 8 weeks. Smaller projects like extensions tend to be approved more quickly, while larger developments can take longer.
Based on approved applications with recorded decision dates over the last 3 months.
Domestic vs Commercial Projects in Welwyn Hatfield
In Welwyn Hatfield, the vast majority (82%) of planning applications are domestic projects such as extensions and loft conversions. Commercial developments make up a smaller portion but can offer higher-value opportunities for larger contractors.
Demand for Building Work in Welwyn Hatfield
Welwyn Garden City's planned garden-city housing stock supports a steady, well-established extension and loft conversion market, while Hatfield's ongoing university and business park development around the former de Havilland site continues to bring commercial and institutional construction opportunities into the borough. Together, the two towns give Welwyn Hatfield a broader mix of residential and commercial-facing construction activity than many comparable Hertfordshire boroughs.
How to Win Jobs in Welwyn Hatfield
Contact Homeowners Early
Planning applications highlight upcoming work, giving you a chance to get in touch before builders are shortlisted.
Focus on Approved Applications
Approved applications can be particularly valuable because the project has cleared a major planning hurdle and may be moving closer to construction.
Target Higher-Value Projects
Filter by estimated project value to focus your outreach on jobs that match the size and type of work your business takes on.
How BuildAlert Works
Three simple steps to start winning more construction work in Welwyn Hatfield.
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We monitor Welwyn Hatfield Borough Council and surrounding authorities daily for new residential projects.
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Contact Homeowners
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Nearby Areas
Builders based in Welwyn Hatfield often take on work in nearby Hertfordshire areas such as St Albans, Hertsmere, and Stevenage, helping maintain a consistent flow of projects.
Frequently Asked Questions
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