Updated 8 October 2026 · 76 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.
76
New Leads (30 Days)
£131,618
Average Project Value
17
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 42 of the 76 leads tracked in the last 30 days, with Garden Rooms also showing consistent demand alongside Garage Conversions. 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
- 4L Architects
- 5G2 Architecture
- 6Principlanning
- 7JMD Building Consultancy
- 8Archimedes design
- 9Kappa Planning Ltd
- 10Argento Design Studio Ltd
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 |
|---|---|---|---|---|
| Single Storey Rear Extension | 16 The Wade Welwyn Garden City AL7 4LG | £50k–£100k | Erection of a garden room and a single storey rear extension after demolishing conservatory. | Approved |
| Single Storey Rear Extension | Welwyn Hatfield | £50k–£100k | Proposed single storey rear extension and garden room after demolishing conservatory. | Approved |
| 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 |
| Single Storey Rear Extension | 47 Puttocks Drive Welham Green Hatfield AL9 7LW | £50k–£100k | Erection of a single storey rear extension. | Approved |
| Wrap-Around Extension | 9 Mardley Hill Welwyn AL6 0UE | £250k–£1m | Erection of single storey front, side and rear extension, raising roof and formation of rear dormer. | Approved |
Single Storey Rear Extension
16 The Wade Welwyn Garden City AL7 4LG
Erection of a garden room and a single storey rear extension after demolishing conservatory.
Single Storey Rear Extension
Welwyn Hatfield
Proposed single storey rear extension and garden room after demolishing conservatory.
Rear Extension
Unit 3 Woodside Lane Hatfield AL9 6DE
Retention of an extension and erection of a rear extension following demolition of existing buildings.
Single Storey Rear Extension
47 Puttocks Drive Welham Green Hatfield AL9 7LW
Erection of a single storey rear extension.
Wrap-Around Extension
9 Mardley Hill Welwyn AL6 0UE
Erection of single storey front, side and rear extension, raising roof and formation of rear dormer.
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 | 41 Great North Road Welwyn Garden City AL8 7TJ | £50k–£100k | Certificate of lawfulness for proposed hip-to-gable loft conversion with rear dormer, single-storey side extension and front rooflight. | Approved |
| Loft Conversion | 7 Tolmers Road Cuffley Potters Bar EN6 4JF | £50k–£100k | Hip-to-gable roof extension with rear box dormer and three front rooflights. | 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
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
41 Great North Road Welwyn Garden City AL8 7TJ
Certificate of lawfulness for proposed hip-to-gable loft conversion with rear dormer, single-storey side extension and front rooflight.
Loft Conversion
7 Tolmers Road Cuffley Potters Bar EN6 4JF
Hip-to-gable roof extension with rear box dormer and three front rooflights.
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.
Other Projects
| Project Type | Area | Est. Value | Description | Status |
|---|---|---|---|---|
| Heritage | 14 Fore Street Hatfield AL9 5AH | £25k–£50k | Repointing and brick replacement on the principal front elevation and rear gable. | Withdrawn |
| New Build | 31A Howardsgate Welwyn Garden City AL8 6AP | £250k–£1m | Proposal to add a second floor to create 3 residential units with internal access alterations. | Refused |
| Garden Room | Essendon Place London Lodge High Road Essendon Hatfield AL9 6HU | £50k–£100k | Erect single-storey outbuilding with roof accommodation following demolition of existing outbuilding. | Refused |
| Garage Conversion | 21 The Swallows Welwyn Garden City AL7 1BX | £25k–£50k | Garage conversion with alterations to front and rear openings. | Approved |
| Garden Room | Welwyn Hatfield | £25k–£50k | Replace existing shed with a garden office/workshop (outbuilding) in the rear garden. | Approved |
Heritage
14 Fore Street Hatfield AL9 5AH
Repointing and brick replacement on the principal front elevation and rear gable.
New Build
31A Howardsgate Welwyn Garden City AL8 6AP
Proposal to add a second floor to create 3 residential units with internal access alterations.
Garden Room
Essendon Place London Lodge High Road Essendon Hatfield AL9 6HU
Erect single-storey outbuilding with roof accommodation following demolition of existing outbuilding.
Garage Conversion
21 The Swallows Welwyn Garden City AL7 1BX
Garage conversion with alterations to front and rear openings.
Garden Room
Welwyn Hatfield
Replace existing shed with a garden office/workshop (outbuilding) in the rear garden.
Data sourced from Welwyn Hatfield Borough Council planning records and refreshed regularly.
Featured Projects
A snapshot of recent construction opportunities across Welwyn Hatfield.
Proposed single storey rear extension and garden room following demolition of conservatory together with the retention of the single storey front porch and side extension.
£50k–£100k16 The Wade Welwyn Garden City AL7 4LG
Erection of a garden room and a single storey rear extension after demolishing conservatory.
Proposed single storey rear extension and garden room following demolition of conservatory
£50k–£100kWelwyn Hatfield
Proposed single storey rear extension and garden room after demolishing conservatory.
Repointing of the principal front elevation. Localised repointing of approximately 2m of brickwork in the rear gable. Replacement of 20 damaged bricks to the chimney stacking reclaimed bricks to match the existing. Careful removal of failed pointing by hand Repointing using a lime-based mortar to match the original in composition. Pre-wetting of joints using a mist spray. Finishing of mortar joints flush with the the brick face.
£25k–£50k14 Fore Street Hatfield AL9 5AH
Repointing and brick replacement on the principal front elevation and rear gable.
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.
Examples of projects at an early stage before wider competition builds.
See All 76 Construction Leads in Welwyn Hatfield
Unlock full details and connect with homeowners while projects are still taking shape.
Get Access NowPlanning Application Status in Welwyn Hatfield
40%
Approved
53%
Pending
7%
Refused
In Welwyn Hatfield, 40% of planning applications are approved, 53% are still pending, and 7% 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 (88%) 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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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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