Urban Greening Factor Calculations for London Planning

What the Urban Greening Factor is

The Urban Greening Factor (UGF) is the GLA's score for how much greening a development provides, and how good it is. Trees, green roofs, planting, rain gardens and water all count. Concrete and tarmac count for nothing.

London Plan Policy G5 asks major developments to make greening a basic part of the site and building design, and to show it with a UGF score. The method is set out in the GLA's Urban Greening Factor London Plan Guidance (February 2023).

Who needs it, and the target

The UGF applies to all major development: usually 10 or more homes, or 1,000 m² or more of new floor space. Some boroughs also ask for it on smaller schemes through their Local Plan.

Where the borough hasn't set its own target, the London Plan defaults apply:

• 0.4 for predominantly residential development (including student housing, co-living and assisted living).
• 0.3 for predominantly commercial development (including hotels and institutional buildings).
• Predominantly industrial development (B2 and B8) is excluded under the 2021 London Plan.

On a mixed-use scheme, the use with the largest floor space sets the target. Boroughs can set their own scores, but they have to keep the GLA's method and factors.

How the score is worked out

1. Each surface on the site is given a surface cover type and its factor.
2. We measure the area of each one in m².
3. Each area is multiplied by its factor.
4. The results are added up.
5. The total is divided by the whole site area inside the red line.

The GLA factors are:

• Semi-natural vegetation (trees, woodland, species-rich grassland): 1.0
• Wetland or open water (semi-natural, not chlorinated): 1.0
• Intensive green roof (at least 150 mm substrate): 0.8
• Standard trees in pits, soil volume at least two-thirds of mature canopy: 0.8
• Extensive green roof to the GRO Code 2014: 0.7
• Flower-rich perennial planting: 0.7
• Rain gardens and other vegetated SuDS: 0.7
• Hedges: 0.6
• Standard trees in pits, smaller soil volume: 0.6
• Green walls (modular or soil-rooted climbers): 0.6
• Groundcover planting: 0.5
• Amenity grassland: 0.4
• Lightweight sedum roof (not to the GRO Code): 0.3
• Chlorinated water features, unplanted detention basins: 0.2
• Permeable paving (including blue roofs): 0.1
• Sealed surfaces (concrete, asphalt, artificial grass): 0

Quality beats quantity. A smaller area of good greening can score the same as a large area of grass.

What planning wants to see

• A UGF plan: the site plan colour-coded by surface cover type. The landscape masterplan on its own isn't enough.
• A UGF table, using the GLA's UGF calculator, with enough detail for the officer to check every area.
• Assumptions stated, for example tree canopy size at planting, and figures not rounded.

On outline applications the score is worked out from the illustrative landscape plan, and a condition usually asks for the final calculation at reserved matters. Phased schemes show that each phase delivers its share.

Where schemes go wrong

These are the points officers pick up most often:

• Using part of the site instead of the whole red-line area.
• Counting land outside the red line.
• Leaving out retained trees and planting.
• Adding green wall area to the site area.
• Counting tree canopy where the trunk is off site.
• Using the wrong target on a mixed-use scheme.
• Claiming a high-value habitat, such as species-rich grassland, with no management plan to back it up.

Getting to the target

On a dense site, most of the score has to come from the roofs and the edges. The main levers are:

• The roof. An extensive green roof to the GRO Code scores more than double a lightweight sedum roof. A biosolar roof lets solar PV and greening share the same space, which matters when the energy statement needs the PV.
• Trees with real soil volume. Bigger tree pits move a tree from 0.6 to 0.8.
• Rain gardens and swales score 0.7 and help the drainage strategy at the same time.
• Permeable paving instead of sealed paving for paths and parking.

If the target still can't be met, planning expects you to explain why. Off-site greening or a financial contribution is possible, but it is not the main route.

What we do, and what we don't

• We do: the UGF calculation, the UGF table and the colour-coded UGF plan from your landscape or site plan, and options to close the gap if the score is short, checked against the roof PV and overheating strategy.
• We don't: design the landscaping, choose the planting or write the ecology report. That's your landscape architect and ecologist.

UGF and Biodiversity Net Gain are separate. Passing one doesn't mean passing the other, and planning wants evidence for both.

Why it links to the energy work

Greening and energy compete for the same roof and the same site. Green roofs and trees also help with overheating, and the GLA's cooling hierarchy puts shading and green infrastructure ahead of air conditioning. Doing the UGF with the energy statement and the TM59 means the roof plan works for all three.

What's changing: the draft London Plan

Checked 14 November 2026.

The draft new London Plan (published 16 July 2026, consultation closed 15 October 2026) keeps the Urban Greening Factor in draft Policy GHR7, with the same 0.4 residential and 0.3 commercial targets, and adds a target of 0.2 for predominantly industrial development. It also says UGF and Biodiversity Net Gain are complementary and should be assessed and reported separately. Until the new plan is adopted, the London Plan 2021 targets apply.

What we need from you

• The site plan with the red line boundary.
• The landscape plan, or the proposed site layout if there is no landscape plan yet.
• Roof plans, and the green roof build-up and substrate depth if known.
• Tree sizes and tree pit details, and any trees or planting being kept.
• The borough's UGF target, if it has its own.

Price and turnaround

No fixed price: it depends on the size of the site. Send the details for a free quote. Turnaround is 5 working days once we have everything we need.

Need the energy statement, Air Quality Neutral assessment or TM59 too? We price them together.

Our experience

More than 17 years in energy assessment, with a mechanical engineering background, and more than 50 energy statements for planning. We know what London planning officers check, and we keep the UGF, the roof PV and the overheating strategy working from the same plans.

Questions we get asked

Does my scheme need a UGF calculation?
If it is a major development in London, yes. Under 10 homes, only if your borough's Local Plan asks for it. Check the validation checklist, or send it to us.

Do green walls count?
Yes, at 0.6. The wall area counts towards the score but is not added to the site area. Green walls also have to meet the fire safety rules.

Can we count the street trees outside the site?
No. Only greening inside the red line counts. A tree canopy can count where the trunk is on site.

Is a sedum roof enough?
Often not. A lightweight sedum roof scores 0.3. An extensive green roof built to the GRO Code scores 0.7, and an intensive one 0.8.

Related: Air Quality Neutral assessments · Carbon Reduction Plans (PPN 006) · Energy statements · Community heating feasibility · The London Plan energy hierarchy · TM59 dynamic overheating · Overheating assessments · Solar PV for SAP and SBEM · New dwellings · Energy assessments in London · Industry updates

Email your site plan and landscape plan, or WhatsApp us, for a free quote.