17-17A Mill Lane Welwyn AL6 9EU Data via plota.co.uk

6/2026/1370/LAWP - LAWFUL DEVELOPMENT - PROPOSED Approved
Change of useNew homesCommercial premises

Proposal

Certificate of lawfulness for the change of use of offices to 3 x 2 bedroom flats Data via plota.co.uk

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View original council record ↗Last checked

Application progress

✓
Received
3 Aug 2026
✓
Validated
5 Aug 2026
✓
Approved
10 Sept 2026

Approved on 10 Sept 2026 · Delegated · Last checked 16 Oct 2026

Documents 10

Decision & officer reports 2

PDF Decision Notice_620261370LAWP.pdf (719 kb) Document · 10 Sept 2026 View ↗ PDF Delegated Report_620261370LAWP(1).pdf (247 kb) Document · 10 Sept 2026 View ↗

Statements & assessments 1

PDF Planning Statement.pdf (1114 kb) Document · 3 Aug 2026 View ↗

Plans & drawings 4

PDF AT1155-01 site plan and location plan.pdf (152 kb) Document · 3 Aug 2026 View ↗ PDF AT1155-02 existing floor plans.pdf (116 kb) Document · 3 Aug 2026 View ↗ PDF AT1155-03 proposed floor plans RevB.pdf (142 kb) Document · 3 Aug 2026 View ↗ PDF AT1155-04 existing and proposed elevations RevA.pdf (127 kb) Document · 3 Aug 2026 View ↗

Consultation & comments 1

PDF Comments.pdf (74 kb) Document · 2 Sept 2026 View ↗

Other documents 2

PDF ApplicationFormRedacted.pdf (227 kb) Document · 3 Aug 2026 View ↗ PDF Deemed consent letter.pdf (186 kb) Document · 3 Aug 2026 View ↗

All documents on the council site ↗

Site constraints 5

Grade II listed: Ebenezer Strict Baptist Church
List entry 1100939 · 14 m away · 35 more listed buildings within 150 m (35 Grade II)
Listed building consent is needed for work that affects the special interest of a listed building, inside or out, on top of planning permission. Setting can be a consideration for buildings nearby; there is no fixed radius.
Show the other 35 with distances
Historic England ↗
Welwyn conservation area
Demolition needs planning permission and permitted development is restricted.
The council must give weight to preserving or enhancing the area's character and appearance. Not every council has published its boundaries as open data.
Council document ↗
Local nature reserve 295 m away: Singlers Marsh
Work nearby can need a habitats assessment.
Harm to a protected site is only accepted where there is no alternative and an overriding public interest.
Also on the record
Radon affected area, class 2; Inside the Welwyn built-up area.
Not affected
Outside flood zones 2 and 3 · Not green belt · No scheduled monument at the site

Checked on 6 October 2026. Historic England, the Environment Agency, Natural England, the British Geological Survey and UK Health Security Agency (radon, contains BGS materials © UKRI) and council datasets, Open Government Licence. A boundary can run through a site and the council holds the definitive record: confirm with the council before relying on this.

Building

Floor area252 m² (2,713 sq ft)
Energy ratingC (asset rating 69)
UseOffices and Workshop Businesses
HeatingHeating and Natural Ventilation

From the energy performance certificate lodged in July 2024, the latest held for this property. The building may have changed since. View the certificate

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Other new applications on this street

25 Sept 2026Pending

28 Mill Lane Welwyn AL6 9ET

1 x Magnolia to reduce 1.5m width and height.

6/2026/1685/TC
22 Sept 2026Pending

Parkside House 58 Mill Lane Welwyn AL6 9ES

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6/2026/1676/TC
1 May 2026Approved

44 Mill Lane Welwyn AL6 9ET

TG1 Sycamore, Prunus and Hazel - Coppice/pollard the Sycamore and Hazel to the h...

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Important details

Council
Welwyn Hatfield
Application type
LAWFUL DEVELOPMENT - PROPOSED
Postcode
AL6 9EU
Received
3 Aug 2026
Validated
5 Aug 2026
Parish
Welwyn
Case officer
Show
Decision
Granted
Decision date
10 Sept 2026
Decision level
Delegated
Applicant
Show
Agent
Show

How this decision compares

Decided in 36 days from validation, 20 days faster than Welwyn Hatfield's median of 56 for changes of use. Approved, as 63% of changes of use here are.

51%decided within 8 weeks
63%approved
42decided in the last year

Plota live figures for changes of use decided by Welwyn Hatfield in the last twelve months, from validation. Welwyn Hatfield decision record →

Public comments

1comment received

Last counted 16 Oct 2026

Read the comments on the council site ↗

Consultation & key dates

Comments by
12 Aug 2026

Historical activity at this location

30 previous applications on record - archival context, not part of the live application.

This property

Previous applications at this address

2023 Withdrawn
Change of use from commercial, business and service (Class E) to dwellinghouses (Class C3…
6/2023/2232/PN33
2023 Withdrawn
Change of use from commercial, business and service (Class E) to dwellinghouses (Class C3…
6/2023/2232/PN33
2018 Approved
Prior approval for change of use from office building B1 to dwelling houses C3
6/2018/1454/PN11
2016 Refused
Prior approval for the change of use from office to residential to provide 3no two bedroo…
6/2016/1611/PN11
2016 Refused
Prior approval for the change of use from office to residential to provide 3no two bedroo…
6/2016/1611/PN11
Within ~100m

Nearby activity

2025 Approved
The Old Rectory 23-25 Mill Lane Welwyn AL6 9EU
Erection of a single storey rear extension and new detached garage with associated extern…
6/2025/1212/HOUSE
2025 Approved
The Old Rectory 23-25 Mill Lane Welwyn AL6 9EU
Erection of a single storey rear extension and new detached garage with associated extern…
6/2025/1212/HOUSE
2025 Approved
44 Mill Lane Welwyn AL6 9ET
T1. Mulberry - Pollard back to historic points. T2. Ash - Cut back the overhanging branch…
6/2025/2006/TC
2025 Approved
44 Mill Lane Welwyn AL6 9ET
T1. Mulberry - Pollard back to historic points. T2. Ash - Cut back the overhanging branch…
6/2025/2006/TC
2025 Approved
The Old Rectory 23-25 Mill Lane Welwyn AL6 9EU
Refurbishment and reconfiguration of existing Grade II listed building, demolition of exi…
6/2025/1211/LB
2025 Approved
The Old Rectory 23-25 Mill Lane Welwyn AL6 9EU
Refurbishment and reconfiguration of existing Grade II listed building, demolition of exi…
6/2025/1211/LB
2025 Approved
28 Mill Lane Welwyn AL6 9ET
T1. Magnolia - Shape and balance the crown of the tree by bringing in selective limbs on…
6/2025/1507/TC
2025 Approved
28 Mill Lane Welwyn AL6 9ET
T1. Magnolia - Shape and balance the crown of the tree by bringing in selective limbs on…
6/2025/1507/TC
2025 Approved
The Old Rectory 23-25 Mill Lane Welwyn AL6 9ET
Repair existing window frames, replace existing single glazing with slimline double glazi…
6/2025/0832/LB
2025 Approved
The Old Rectory 23-25 Mill Lane Welwyn AL6 9ET
Repair existing window frames, replace existing single glazing with slimline double glazi…
6/2025/0832/LB
2025 Withdrawn
The Old Rectory 23-25 Mill Lane Welwyn AL6 9EU
Erection of single storey rear and side extension, conservatory and new detached garage w…
6/2025/0586/HOUSE
2025 Withdrawn
The Old Rectory 23-25 Mill Lane Welwyn AL6 9EU
Erection of single storey rear and side extension, conservatory and new detached garage w…
6/2025/0587/LB
2025 Withdrawn
The Old Rectory 23-25 Mill Lane Welwyn AL6 9EU
Erection of single storey rear and side extension, conservatory and new detached garage w…
6/2025/0586/HOUSE
2025 Withdrawn
The Old Rectory 23-25 Mill Lane Welwyn AL6 9EU
Erection of single storey rear and side extension, conservatory and new detached garage w…
6/2025/0587/LB
2025 Approved
6 Mimram Road Welwyn AL6 9HA
Remove tiles and battens to rear roof, repair existing rafters, refit roof tiles and batt…
6/2025/0286/LB
2025 Approved
6 Mimram Road Welwyn AL6 9HA
Remove tiles and battens to rear roof, repair existing rafters, refit roof tiles and batt…
6/2025/0286/LB
2025 Approved
Parkside Cottage 56 Mill Lane Welwyn AL6 9ES
Repairs to crenelation structures and copings on westerly elevation
6/2025/0222/LB
2025 Approved
Parkside Cottage 56 Mill Lane Welwyn AL6 9ES
Removal of existing sand and cement render on gable end of north elevation, re-lath with…
6/2025/0223/LB
2025 Approved
Parkside Cottage 56 Mill Lane Welwyn AL6 9ES
Repointing work to existing garden boundary wall
6/2025/0224/LB
2025 Approved
Parkside Cottage 56 Mill Lane Welwyn AL6 9ES
Repairs to crenelation structures and copings on westerly elevation
6/2025/0222/LB
2016 Approved
16 Mill Lane Welwyn AL6 9ET
Erection of single storey rear extension and replacement window to Bathroom
6/2016/1900/HOUSE
2016 Approved
28 Mill Lane Welwyn AL6 9ET
Prune T1 Magnolia tree located at the rear of house according to the following specificat…
6/2016/2223/TPO
2016 Approved
28 Mill Lane Welwyn AL6 9ET
Prune T1 Magnolia tree located at the rear of house according to the following specificat…
6/2016/2223/TPO
2016 Approved
The Mill House 31 Mill Lane Welwyn AL6 9EU
Removal of Limb from Yew tree, crown reduce Sycamore tree crown by 30% plus fell two Coni…
6/2016/0611/TPO
2016 Approved
The Mill House 31 Mill Lane Welwyn AL6 9EU
Removal of Limb from Yew tree, crown reduce Sycamore tree crown by 30% plus fell two Coni…
6/2016/0611/TPO
Welwyn Hatfield
Planning Authority Score
2.1/10
Poor
#272 of 296 councils
Relevant to this application:
Change of use

Welwyn Hatfield is slower than most councils at deciding householder applications, ranking #224 out of 296. 50% of applications have the time limit extended, above the 41% national average. Householder applications are slightly less likely to be approved here (86%) than the national average (90%).

Slower than most councils
for householder decisions
These figures are council-wide context, not a prediction for this application. View full council performance
Welwyn Hatfield decision statistics
Based on MHCLG data, the year to March 2026
86%
Overall approval rate
Below avg (87%) #200 of 296
86%
Householder approved
Below avg (90%) #246 of 296
53%
Decided in 8 weeks
Below avg (63%) #224 of 296
50%
Extended time limit
Above avg (41%) #229 of 296
84%
Minor dwellings approved
63 decided (1-9 homes)
83%
Major dwellings approved
12 decided (10+ homes)
73%
Change of use approved
22 decided
633
Total decisions
87 refused in the year to March 2026
Source: MHCLG planning statistics · See full council rankings

Energy performance: Energy performance certificates from the Energy Performance of Buildings Register, Ministry of Housing, Communities and Local Government. Contains public sector information licensed under the Open Government Licence v3.0. © Crown copyright 2026.