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Three Rivers, Hertfordshire

Architectural drawings in Three Rivers

Three Rivers has a Green Belt guidance note written specifically for house extensions, and 76 per cent of the district is Green Belt. Our architectural drawings in Three Rivers start from £745 including VAT and are drawn to that note. We are MCIAT chartered architectural technologists, and the first check of your address is free.

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    Upper floors of a large yellow-brick Victorian house in London with chimney pots

    Three Rivers in numbers

    Figures with their unit, period and source
    MeasureValuePeriodSource
    Green Belt share of the council area76 % of council area covered by green-belt polygons—planning.data.gov.uk
    Conservation areas19 named conservation areas published by the council—planning.data.gov.uk
    Listed building entries352 list entries (Historic England, within the LPA boundary)—planning.data.gov.uk
    Householder decisions617 decisions1 July 2025 - 30 June 2026assets.publishing.service.gov.uk
    Householder applications granted90.9 %1 July 2025 - 30 June 2026assets.publishing.service.gov.uk
    Householder applications decided in time98.1 % decided within 8 weeks or an agreed extended period1 July 2025 - 30 June 2026assets.publishing.service.gov.uk
    Larger home extension prior approvals granted11 decisions2025 Q2 to 2026 Q1 (1 Apr 2025 to 31 Mar 2026)assets.publishing.service.gov.uk
    Lawful development certificate applications (PS1)192 certificates2025 Q2 to 2026 Q1 (1 Apr 2025 to 31 Mar 2026)assets.publishing.service.gov.uk
    Households living in a house79.7 % of households living in a house or bungalow (detached, semi-detached or terraced)Census 2021nomisweb.co.uk
    Average price, detached1,206,251 GBP2026-07publicdata.landregistry.gov.uk
    Local planThree Rivers Local Plan: Core Strategy (2011), Development Management Policies LDD (2013) and Site Allocations LDD (2014)—threerivers.gov.uk
    Supplementary planning documentSPG 3: Green Belt (extensions to dwellings)—threerivers.gov.uk
    Borough CIL charging scheduleThree Rivers CIL Charging Schedule (adopted February 2015)from 2015-04-01threerivers.gov.uk

    A blank value means the figure has not been published, not that there are none. Check your own address with the council.

    Councils bordering Three Rivers
    Constraints check: Three RiversConservation areas: 19 named conservation areas published by the council. Listed building entries: 352 list entries (Historic England, within the LPA boundary)19Conservation areasA352Listed building entriesC

    Constraints check: Three Rivers

    What we check first on any Three Rivers address. Counts are for the whole council area.

    A · Conservation areas
    19 named conservation areas published by the council
    C · Listed building entries
    352 list entries (Historic England, within the LPA boundary)

    Three Rivers' Green Belt guidance for extensions

    The council's supplementary document for this is SPG 3: Green Belt (extensions to dwellings). It is the first thing we open for a Three Rivers extension, because it governs how much a home can grow when the land around it is protected.

    Its tests are about proportion and openness, so the drawing set has to show the original house clearly: the footprint, the roof and any earlier additions. We mark these on the plans, so the officer does not have to reconstruct the history of the building from old applications.

    With so much of the district in the Green Belt, many homes here meet this test whatever the project.

    Rows of brick terraced houses and gardens on a residential street

    The local plan behind Three Rivers decisions

    Policy comes from the Three Rivers Local Plan: Core Strategy (2011), Development Management Policies LDD (2013) and Site Allocations LDD (2014). The core strategy dates from 2,011, and the later documents fill in detail on development management and allocated sites.

    In practice that means a design is read against several documents at once. We list the relevant policies in the design note that goes with the drawings, so you can see what the council will weigh.

    How fast and how often Three Rivers decides yes

    The council decided 617 householder applications between July last year and June this year, and 90.9 per cent were granted. Timing stands out: 98.1 per cent were decided within eight weeks or an agreed extension.

    For minor applications the in-time figure was 98.4 per cent, with 82.1 per cent granted. A quick decision helps a builder plan the start date, though it does not alter what the officer decides.

    These are past figures for the district. They are not a promise for your house.

    Prior approval and lawful development in Three Rivers

    Larger home extensions can use prior approval. In the latest published year the council granted 11 and refused 14, a split that rewards a careful neighbour assessment.

    Owners also applied for 192 lawful development certificates that year. If you are building under permitted development, a Lawful Development Certificate in Three Rivers is the written proof.

    Heritage in Three Rivers

    The council publishes 19 conservation areas. Historic England lists 352 entries: 3 at Grade I, 14 at Grade II* and 333 at Grade II.

    There are also 2 registered parks and gardens, 3 scheduled monuments and 1 entry on the Heritage at Risk Register. If your house is listed or sits in a conservation area, we explain which consents apply before you spend on design.

    From first call to submission in Three Rivers

    Send the address and a few lines on what you want. We reply the same working day if your message arrives before three in the afternoon, and we report back on the planning constraints before any fee is taken for design.

    Drawings follow in about seven days after the survey. You review them, we adjust, and the independent check is done by someone who did not draw the set. Only then does the application go to the council, through the Planning Portal, with the forms and certificates completed.

    Should the council ask for changes, our redraws are free until approval.

    Levy, prices and housing in Three Rivers

    Three Rivers charges the Community Infrastructure Levy under its Three Rivers CIL Charging Schedule (adopted February 2015), with three residential areas. The charge is highest in Area A, lower in Area B and nil in Area C.

    79.7 per cent of households live in a house or bungalow, and 70.9 per cent own their home. A detached house averages £1,206,251 and a terraced one £461,977.

    The architectural drawings we prepare in Three Rivers

    Typical work includes planning drawings in Three Rivers, side return extension drawings and double-storey extension drawings. For the build, construction drawings turn the permission into a set a builder can price.

    Over the border, see our council pages for Buckinghamshire, Hillingdon and Hertsmere.

    What you receive

    Planning drawing sheet for a rear extension with plans, elevations and sections
    Sample drawing. Planning drawings for a rear extension: plans, elevations and sections on one sheet set.
    Georgian brick terrace with sash windows, arched fanlight doorways, stone steps and iron railings in London
    The street around you
    Move across the plinth — the blocks rise around the pointer.

    Questions

    Can I extend a house in the Green Belt in Three Rivers?

    Often, within limits. The council's SPG 3: Green Belt (extensions to dwellings) sets the test, and we design to it after measuring the original house.

    How much are architectural drawings in Three Rivers?

    Householder planning drawings start at £745 including VAT, fixed up front. The council's own application fee is separate.

    Does Three Rivers charge the Community Infrastructure Levy?

    Yes, in three residential areas under its Three Rivers CIL Charging Schedule (adopted February 2015). We tell you which area applies and whether your project is liable.

    How long does Three Rivers take to decide a householder application?

    In the latest figures 98.1 per cent were decided within eight weeks or an agreed extension. That describes the past, not your case.

    Sources and dates

    City of London skyline glowing at dusk across the Thames under a dramatic orange sky

    Tell us about your property.

    We check the constraints, then send a fixed fee. Messages before 3pm get a reply the same working day.