Back-of-house extension drawings for North Hertfordshire homes — the glazed kitchen-diner across the rear, drawn to North Hertfordshire District Council's depth and daylight limits, delivered in days and revised free until your decision, with a free approval-odds check first.
North Hertfordshire District Council granted 95% of the householder planning decisions it made in its latest published year — 8 points above the 87% England-wide householder average. North Hertfordshire contains Ashwell, Baldock, Barkway conservation areas (Ashwell designated 1968), so materials, fenestration and roof form are assessed against the appraisal, which is where a policy-literate drawing pack earns its keep. Its dominant Victorian (1837–1901) housing stock sets the design brief on most streets.
The permitted-development ceilings are fixed: 40m³ of new roof volume for a terraced loft and 50m³ for a semi or detached house under Class B, plus a 3m single-storey rear extension on a terrace or 4m on a detached house under Class A. In conservation areas such as Ashwell, Baldock and Barkway those rights are removed, so we confirm your exact address before a line is drawn. A validated householder application in North Hertfordshire is determined against an 8-week statutory target.
Ashwell (conservation area designated in 1968), Baldock (conservation area designated in 2003), Barkway (conservation area designated in 1970), Barley (conservation area designated in 1969), Bendish (conservation area designated in 1990), Butts Close, Hitchin (conservation area designated in 2011), Charlton (conservation area designated in 1977), Codicote (conservation area designated in 1979), Arbury (ward of North Hertfordshire), Baldock West (ward of North Hertfordshire), Cadwell (ward of North Hertfordshire), Codicote & Kimpton (ward of North Hertfordshire), Ermine (ward of North Hertfordshire), Hitchin Priory (ward of North Hertfordshire), Hitchwood (ward of North Hertfordshire) and Knebworth (ward of North Hertfordshire) — these are the North Hertfordshire pockets our drawings cover most. Heritage designations here include Ashwell, Baldock, Barkway, Barley, Bendish, Butts Close, Hitchin, Charlton and Codicote. North Hertfordshire District Council weighs each proposal against the adopted North Hertfordshire local plan and North Hertfordshire District Council's design guidance for householder work, where the 24,910 homes here are 11% pre-1900, 6% 1983-1992, 6% 1973-1982, which is what sets the realistic roof and rear-projection options. On roofs the borough is steeply pitched slate roofs, valley gutters and party parapets typical of pre-1900 building and trussed-rafter roofs typical of 1980s building, over Victorian and earlier houses (11% of 24,910 homes), 1980s estate houses (6%) and 1970s and early-1980s houses (6%).
Before anything is drawn we check your address against the designations that apply in North Hertfordshire: Ashwell (conservation area designated in 1968), Baldock (conservation area designated in 2003), Barkway (conservation area designated in 1970), Barley (conservation area designated in 1969), Bendish (conservation area designated in 1990), Butts Close, Hitchin (conservation area designated in 2011), Charlton (conservation area designated in 1977) and Codicote (conservation area designated in 1979). Inside those boundaries permitted development is curtailed and North Hertfordshire District Council assesses materials, window detail and roof form against the area's own appraisal, so a scheme that would be waved through two streets away can need a full application here.
Beyond the designated areas, North Hertfordshire takes in Arbury, Baldock West, Cadwell, Codicote & Kimpton, Ermine, Hitchin Priory, Hitchwood and Knebworth. No Article 4 direction is recorded for North Hertfordshire District Council, but the district's 8 conservation areas still limit permitted development on those streets.
On stock, North Hertfordshire is Victorian and earlier houses (11% of 24,910 homes), 1980s estate houses (6%) and 1970s and early-1980s houses (6%) — which is why steeply pitched slate roofs, valley gutters and party parapets typical of pre-1900 building and trussed-rafter roofs typical of 1980s building govern what a loft or rear projection can realistically be. North Hertfordshire District Council decided 665 householder applications in the latest published year and granted 95%, with 69% issued inside the eight-week target. That decision record, not a national figure, is what we design to.
The full build-period split for North Hertfordshire runs pre-1900 3% (190 homes), 1900-1918 0% (30 homes), 1919-1929 0% (10 homes), 1930-1939 6% (350 homes), 1945-1954 3% (170 homes), 1955-1964 30% (1,850 homes), 1965-1972 33% (1,990 homes), 1973-1982 4% (260 homes), 1983-1992 5% (310 homes), 1993-1999 4% (220 homes) and 2000-2008 3% (170 homes). That distribution is why pre-1900 detailing dominates the drawings here, and it is measured from council-tax records rather than assumed from the street name.
North Hertfordshire District Council also decides for Arbury, Baldock West, Cadwell, Codicote & Kimpton, Ermine, Hitchin Priory, Hitchwood and Knebworth, so a decision in North Hertfordshire sits inside a wider pattern of decisions we track across the same authority — useful when an officer cites a precedent from the next area over.
Published figures for North Hertfordshire and North Hertfordshire District Council. These are the numbers that decide what is realistic on your street, so we work from them rather than from national averages.
| Measure | North Hertfordshire |
|---|---|
| Dwellings recorded | 24,910 |
| Built pre-1900 | 190 (3%) |
| Built 1900-1918 | 30 (0%) |
| Built 1919-1929 | 10 (0%) |
| Built 1930-1939 | 350 (6%) |
| Built 1945-1954 | 170 (3%) |
| Built 1955-1964 | 1,850 (30%) |
| Built 1965-1972 | 1,990 (33%) |
| Built 1973-1982 | 260 (4%) |
| Built 1983-1992 | 310 (5%) |
| Built 1993-1999 | 220 (4%) |
| Built 2000-2008 | 170 (3%) |
| Built before 1919 | 21% |
| Built 1919–1939 | 16% |
| Built 1945–2008 | 51% |
| Conservation areas in North Hertfordshire | 8 (Ashwell, Baldock…) |
| Conservation areas district-wide | 44 |
| Article 4 directions recorded | 0 |
| Householder applications decided | 665 |
| Householder applications granted | 95% |
| Decided within 8 weeks | 69% |
Dwelling stock from VOA council-tax data at 31 March 2025; conservation-area and Article 4 counts from planning.data.gov.uk (MHCLG); decision figures are North Hertfordshire District Council's own, from MHCLG live table PS2 for the year to 31 March 2026.
The rear extension is the workhorse of North Hertfordshire home improvement — it is how a dark back kitchen becomes an open family room facing the garden. Because the borough is built largely from Victorian and earlier houses (11% of 24,910 homes), 1980s estate houses (6%) and 1970s and early-1980s houses (6%), most back walls sit close to a neighbour on at least one side, and that proximity, not the design, is what North Hertfordshire District Council scrutinises. The council reads the proposal against the adopted North Hertfordshire local plan and North Hertfordshire District Council's design guidance for householder work, and the first line an officer draws is the 45-degree splay from the neighbour's nearest window.
So the drawings live or die on geometry. We set the depth against the exact permitted-development figure, hold the eaves and the flat-roof or lantern build-up under the 4-metre height ceiling, and show the projection tested against both the 45-degree plan angle and the 25-degree section angle to the neighbouring windows. North Hertfordshire contains Ashwell, Baldock, Barkway conservation areas (Ashwell designated 1968), so materials, fenestration and roof form are assessed against the appraisal, so the rear elevation is composed around it rather than corrected after an objection.
Where the property sits in a conservation area — Ashwell, Baldock, Barkway, Barley, Bendish, Butts Close, Hitchin, Charlton and Codicote among North Hertfordshire's — the larger-home extension route is switched off and even a modest rear addition needs consent. No Article 4 direction is recorded for North Hertfordshire District Council, but the district's 8 conservation areas still limit permitted development on those streets. We confirm the designation before the survey.
Many single-storey rear extensions in North Hertfordshire are permitted development and need no application. You will normally need to apply to North Hertfordshire District Council, or use the larger-home prior-approval route, if any of these apply:
We draw the depth, the roof build-up and the daylight splays to each neighbour on the page — the tests North Hertfordshire District Council's officers apply first — and submit a validation-complete pack, whether that is a lawful development certificate, a larger-home prior-approval notice or a full householder application.
Below is North Hertfordshire District Council's real householder decision record, taken from official planning statistics and refreshed as new data lands. North Hertfordshire District Council granted 95% of 665 householder decisions in the year to 31 March 2026, 69% of them inside eight weeks. Rear extensions turn most often on neighbour daylight and depth, so a drawing pack that proves those tests upfront is decided faster and refused less often than a DIY submission.
Source: MHCLG planning application statistics (householder decisions, England, 1 April 2025 - 31 March 2026). Compare every borough on our London approval-rate league table.
Tell us about your project and get a fixed, no-obligation quote back within one working day. If you don't need planning permission at all, we'll tell you that too — for free.
Across Ashwell, Baldock and Barkway, the approved rear extension is typically a single-storey glazed box within the depth limit, roofed either flat with a lantern or in a shallow mono-pitch, and finished in brick or render to match the host wall. On the borough's victorian and earlier houses (11% of 24,910 homes), keeping the projection to the permitted-development figure often avoids an application entirely; where owners want the full 6 metres, the larger-home route succeeds when the neighbour-consultation period passes without a sustained objection.
The 24,910 homes here are 11% pre-1900, 6% 1983-1992, 6% 1973-1982, which is what sets the realistic roof and rear-projection options. We keep the extension inside the daylight splays, set any glazed roof below the first-floor cill, and retain the garden depth North Hertfordshire District Council expects — so the back elevation answers the amenity case before a neighbour can lodge one. Two-storey rear extensions we draw with the 7-metre boundary gap and privacy screening resolved on the plan.
We draw rear extensions on every street in the borough. A few of the neighbourhoods where North Hertfordshire back-of-house projects come up most often:
Rear extension drawings for Ashwell's conservation area designated in 1968 — depth-checked, daylight-tested and drawn to North Hertfordshire District Council's guidance.
Rear extension drawings for Baldock's conservation area designated in 2003 — depth-checked, daylight-tested and drawn to North Hertfordshire District Council's guidance.
Rear extension drawings for Barkway's conservation area designated in 1970 — depth-checked, daylight-tested and drawn to North Hertfordshire District Council's guidance.
Rear extension drawings for Barley's conservation area designated in 1969 — depth-checked, daylight-tested and drawn to North Hertfordshire District Council's guidance.
Rear extension drawings for Bendish's conservation area designated in 1990 — depth-checked, daylight-tested and drawn to North Hertfordshire District Council's guidance.
Rear extension drawings for Butts Close, Hitchin's conservation area designated in 2011 — depth-checked, daylight-tested and drawn to North Hertfordshire District Council's guidance.
How far you can extend at the back in North Hertfordshire depends on your house type and the route you take. This is how the options compare.
| Route | Depth allowed | Consent needed | What North Hertfordshire District Council checks |
|---|---|---|---|
| Standard permitted development | 3m terrace/semi · 4m detached | Lawful development certificate (optional) | Depth, 4m height, materials |
| Larger-home prior approval | 6m terrace/semi · 8m detached | Prior-approval notice + neighbour consultation | Neighbour objections on amenity |
| Full householder application | Beyond the above, or two-storey | Full planning permission | Daylight (45°/25°), bulk, garden retained |
| Conservation area | Case by case | Full planning permission | Character, roof form, boundary treatment |
The larger-home route is switched off on designated land — conservation areas such as Ashwell and Baldock and Article 4 streets need a full application.
A fixed process built around how North Hertfordshire District Council validates and decides rear-extension applications — most drawings are submission-ready within seven days of survey.
Send us your North Hertfordshire postcode and house type. We confirm your conservation and Article 4 status, how much rear-extension depth you have under permitted development, and score your odds against live North Hertfordshire District Council decisions.
We measure the original rear wall, floor and eaves levels, side and rear boundary distances and the neighbours' window positions — the numbers the depth limit and daylight splays depend on.
Chartered designers develop the single or two-storey rear extension to your brief, drawn inside the permitted-development limits or to North Hertfordshire District Council's extension design guidance, with the daylight angles shown.
We submit the certificate, prior-approval notice or application, handle validation and case-officer queries, and revise the drawings free until North Hertfordshire District Council issues its decision.
Often not. A single-storey rear extension up to 3 metres deep on a terrace or semi, or 4 metres on a detached house, and no higher than 4 metres, is usually permitted development in North Hertfordshire. You will need to involve North Hertfordshire District Council for anything deeper via the larger-home route, for two-storey rear extensions, and for any rear extension in a conservation area such as Ashwell and Baldock, where those permitted-development rights fall away.
The larger-home extension scheme lets a single-storey rear extension reach 6 metres on a terrace or semi, or 8 metres on a detached house — double the standard allowance. It is not automatic: you submit a prior-approval notification to North Hertfordshire District Council, neighbours are consulted, and if one objects on amenity grounds the council rules on it. It also does not apply on designated land such as North Hertfordshire's conservation areas.
It is the daylight test North Hertfordshire District Council applies to protect neighbours. Drawn on plan, a line at 45 degrees from the midpoint of the neighbour's nearest ground-floor window should not be crossed by your extension; a companion 25-degree line is checked in section. If the projection breaches it, the extension is likely to be shortened or refused, so we test and prove it on the drawings before submission.
A two-storey rear extension almost always needs a full householder application to North Hertfordshire District Council, as it sits outside permitted development on most homes. The council checks that it stays at least 7 metres from the rear boundary, does not overbear the neighbours and avoids new overlooking. We resolve the boundary gap, privacy and daylight on the plans so the application is decided on its merits.
Frequently, yes. If the rear extension involves work to a shared wall, building up to the boundary, or excavating foundations near a neighbour's structure, the Party Wall etc. Act applies and you must serve notice — this is separate from North Hertfordshire District Council's planning decision. We flag it early and can prepare the drawings a party-wall surveyor needs alongside the planning set.
We price each North Hertfordshire rear extension on its own footprint and send a fixed, no-obligation quote within one working day. It covers the full drawing pack with free revisions until North Hertfordshire District Council approves, and we confirm at the outset whether your extension is permitted development, needs prior approval, or a full application. Call 020 7864 7245 to begin.
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