Under Blackheath streets the diggable stock is narrower than the postcode suggests: village and heath-edge period houses spanning two boroughs. We filter out leasehold flats first, then test whether a freehold house truly needs below-ground space rather than a rear or loft enlargement toward Greenwich.
The planning frame for Blackheath is Royal Borough of Greenwich / Lewisham: Greenwich or Lewisham authority must be fixed per address. We scope evidence to that authority’s lists and refuse generic “London basement policy” numbers that do not apply to this pin.
Title is the first Blackheath drawing. If the client is a lessee under a freeholder who retains structure and subsoil, we stop the basement brief and redirect to works they can actually consent. Only clear freehold control proceeds to investigation.
We commission plot-specific ground investigation for Blackheath basements: foundation depths, groundwater and obstructions decide the retaining method and whether under-garden elements survive, long before application drawings are fixed.
Because heath-edge character and garden trees, Blackheath basements notify early and often. We map every notifiable owner before a programme date is offered, including internal parties in converted houses.
For Blackheath basements, we treat water as a primary design driver: dual-system waterproofing to BS 8102, twin pumps, backflow protection and ventilation planned with the tanking so the box does not become a sealed cellar.
On Blackheath plots the lightwell package — retaining walls, guarding, steps, grilles — is designed first. Short gardens toward Lewisham and tree constraints can veto a habitable dig even when the structure is sound.
Blackheath clients often arrive asking for a basement when above-ground extensions preferred where gardens remain generous. We price both routes so the dig is a choice, not a default.
Distinctive to Blackheath: village and heath-edge period houses spanning two boroughs combined with heath-edge character and garden trees. That pairing changes bay sequences, spoil routing and which households must be served notices before excavation.
How Greenwich or Lewisham authority must be fixed per address meets the site compound in Blackheath: if the lightwell eats a short garden or trees block the only access, the floor plate shrinks until external works are buildable toward Greenwich.
Do not copy a dig from Greenwich or Lewisham into Blackheath by postcode similarity — Royal Borough of Greenwich / Lewisham evidence thresholds and local grain differ street by street.
Construction hours and vehicle routing on Blackheath streets are written into the package early, because neighbour awards and Royal Borough of Greenwich / Lewisham construction-management expectations often gate the start on site more than the decision notice does.
Blackheath’s first basement sheet is often a Greenwich-versus-Lewisham authority check on the title plan — a dual-borough problem pure SE10 Greenwich freeholds do not share.
Village and heath-edge Blackheath plots more often fail on garden trees and dual flanks than on tourist-core access that dominates Greenwich town digs.
Compared with Deptford or Lee by postcode similarity, Blackheath lightwells are judged against heath-edge character; we write guarding and planting to that grain.
Blackheath programmes sequence dual-LPA fix → freehold subsoil → trees → lightwell → structure. We refuse to import a single-borough Greenwich World Heritage package onto a Lewisham village pin.
Delivery in Blackheath runs investigation and structure before Royal Borough of Greenwich / Lewisham submission, then awards and building regulations; we set that longer programme at the first meeting so the dig is planned as a project, not an add-on. Spoil logistics and temporary works are written into the package rather than discovered at tender.
