Breakdown of typical fees
Council application fee: £116 per submission regardless of how many conditions are bundled. Submit all pre-commencement conditions in one application to minimise fees. Professional preparation: architect or planning consultant time to compile the submission — typically £500–£1,200 for a straightforward extension (materials samples, simple method statement, drainage). £1,500–£3,000 for a project with construction management plan, arboricultural method statement and structural details. £3,000–£8,000+ for listed buildings requiring conservation officer engagement and detailed heritage statements at discharge stage. Specialist consultant fees: arboriculturalist £400–£900 for tree protection method statement; ecologist £500–£1,500 for biodiversity mitigation submission; acoustic consultant £600–£1,800 for noise condition discharge. Material samples (brick, slate, mortar): £150–£500 to source and present.
Conditions that drive the highest discharge cost
Construction Management Plan (CMP): the highest-cost discharge condition on London projects — requires lorry routes, parking restrictions, dust mitigation, working hours, neighbour liaison plan, vehicle wheel washing, hours of delivery. Drafting cost £800–£2,500. Required on most basements, two-storey extensions and listed projects. Pre-commencement arboricultural condition: requires tree protection plan to BS 5837, on-site arboriculturalist presence at sensitive works, root protection methodology. £1,200–£3,500 over the project life. Pre-commencement ecology mitigation: bat surveys (£1,500–£4,000 if seasonal), bird and biodiversity mitigation strategy, hedgehog highway, swift bricks. £2,000–£6,000+. Heritage condition: conservation officer-approved sample panels of brick, mortar joint profile, slate, sash window profile. £1,500–£4,500 in fabrication and conservation officer review. Surface water drainage condition: SuDS strategy, attenuation calculations, soakaway tests. £600–£2,500.
Programme impact
Discharge of planning conditions typically adds 6–10 weeks between planning approval and lawful site start on a residential extension, 10–16 weeks on listed or basement projects. Builderr's standard programme: planning approval week 0, condition discharge submission week 2, full approval week 10, party wall award week 12, site start week 14. Trying to skip or shortcut this stage routinely backfires — enforcement officers actively monitor major sites, and unauthorised commencement creates serious legal exposure. The cost of compliance (a few weeks and a few thousand pounds) is trivial compared with the cost of enforcement or refusal of discharge requiring redesign mid-build.
