Fire, Structural and Basements – Page 13

Mass timber frames at planning stage: fire and insurance

A mass timber structure is a fire, insurance and warranty decision as much as a structural one, and all three need resolving before the planning submission rather than after.

Construction management plans for a basement excavation

Spoil volume drives everything else in a basement construction plan. Write it before the decision, while there is still room to negotiate the conditions.

Basement lightwells, drainage and surface water risk

A lightwell is a surface water inlet before it is anything else. Raised lips, pumped drainage with standby and a real escape route decide the application.

Piling, vibration and neighbouring structures

The vibration levels that annoy neighbours are far below the levels that damage buildings. Method, hours and monitoring are what planning conditions actually control.

Structural condition as an argument for demolition

Condition arguments for demolition usually fail on the same points. What an engineer has to do, how repair schedules are scrutinised, and why marketing evidence matters.

Means of escape and the loft conversion drawing

Adding a loft room turns a two storey house into a three storey one, and the escape rules change at that point. What that does to the stair, the landing and the rooflights.

Fire safety for HMOs at the planning stage

Planning does not regulate fire safety, but the escape strategy decides the HMO floor plan. What to settle before the drawings are submitted, and how licensing and building control overlap.

Eurocode 7 and geotechnical categories in a submission

Geotechnical Category 1, 2 or 3 decides how much ground investigation a site needs. Here is what each covers, how the ground investigation and design reports differ, and what a case officer actually reads.

Demolition prior notification and structural safety

Demolition needs prior approval from the planning authority and a separate notice to building control under the Building Act 1984. Here is what each covers, what the method statement must show, and where conservation areas change the route.

Structural surveys for agricultural building conversions

Class Q turns on whether the existing building can already carry the loads that conversion brings. Here is what the structural report has to show about the frame, the foundations and the works proposed.

Underpinning, party walls and the neighbour's structure

Basement and underpinning work usually engages the Party Wall etc. Act under two sections at once. The notice periods are long enough to derail a programme that treats them as paperwork.

Groundwater and hydrogeology in basement design

Groundwater decides whether a basement is buildable, and the monitoring has to start months before the drawings are finished. Here is what the assessment must establish and what councils expect to see.

Basement policies: single storey limits and garden extent

Where a council has a basement policy, the numbers in it set the design envelope before any engineering evidence is prepared. Here is what those limits usually say and how they are measured.

Sprinklers and the planning consequences of the choice

Sprinklers are treated as a Building Regulations question and settled at planning stage. Tank space, water supply and the trades the decision buys.

External wall materials and the planning application

Regulation 7 limits external wall materials on relevant buildings to the highest fire classifications. What that leaves you, and how to word the materials condition.

BS 9991 and BS 9999: which fire strategy applies

The residential code and the general code diverge on trading, sprinklers and fire service facilities. Where each applies, and how mixed use schemes are handled.

Single staircase residential buildings and the height limit

The second staircase threshold sits at 18 metres, the same height that triggers the fire statement duty and the building safety gateways. Redesigning a consented single stair scheme is usually a section 73 application, not a minor amendment.

Gateways Two and Three: what happens after permission

Planning permission for a higher-risk building only buys the right to apply for building control approval. Gateway Two is a hard stop before work starts, and Gateway Three governs occupation.

The Building Safety Regulator as a planning consultee

At Planning Gateway One the Health and Safety Executive comments on the fire statement as a statutory consultee. Its response is a material consideration, not an approval, and an unanswered adverse response becomes a refusal reason.

The 18 metre and seven storey higher-risk threshold

Height and storeys are alternative limbs, not cumulative. Measurement runs to the top storey floor surface from the lowest adjacent ground level, and mezzanines can count.

What a fire statement must contain under Article 9A

The Article 9A fire statement answers the published form's questions about site layout, appliance access, water supplies and evacuation principles, not building regulations detail.

Planning Gateway One: which buildings are caught

Gateway One catches buildings with two or more dwellings or educational accommodation that reach 18 metres or seven storeys. Both limbs must be satisfied, and measurement decides marginal cases.

10 September 2026Read article →

Retaining walls and level changes: when permission is needed

Level changes and retaining walls are often development under section 55 of the 1990 Act. Fence height rights rarely cover a wall built to hold back earth, and a raised platform above 300 mm needs permission.