Describe the proposal without disguising excavation
The initial survey records accessible lower-ground space, floor levels, entrances and visible construction. We establish how the space is currently used and what information supports that use. The brief then identifies whether the work is a refit, a change of use, floor lowering or an extension beyond the existing enclosure. Those are materially different proposals. A drawing should not present new excavation as if it were simply making better use of an existing room.
Ownership and rights to alter the ground require separate confirmation through the appropriate advisers. A ground-floor position or access to a cellar does not establish that all surrounding subsoil belongs to the dwelling. We record the boundary questions and any shared structures or services that may be affected. This helps determine what investigations are worthwhile and prevents the design developing around an area that the owner cannot assume is available for the proposed work.
Apply current guidance to the correct borough
Hackney's residential alterations SPD took effect in January 2026. Its basement guidance addresses a single-storey form, lightwell design, daylight, gardens, trees and drainage. These considerations are relevant to assessing a Hackney proposal; they are not a promise that an excavation meeting one simple dimension will be approved. We review the full context and the actual property, identifying the evidence and specialist advice needed to develop an appropriate scheme.
Tower Hamlets also contains part of Shoreditch, so Hackney's document cannot be applied to every E1 or E2 address. The site's authority is checked first, followed by its own relevant planning information and designations. The distinction matters particularly where an enquiry relies on advice found for a neighbouring borough. We record which guidance has informed the proposal and avoid converting a local design principle into a universal basement rule.
Sources: Hackney: current residential extensions and alterations SPD · Hackney: basement and lightwell design guidance · Tower Hamlets: East Shoreditch neighbourhood area
Coordinate structure, ground conditions and water
The relevant specialists establish the scope of ground and structural investigation for the actual building and proposed excavation. We identify how the findings influence the extent of work, floor level and support arrangement. Temporary works and sequence need explicit consideration alongside the final structure. The completed-room layout cannot be used as a substitute for explaining how the existing building is supported while material is removed and new construction is installed.
Water management is developed with the proposed use and construction, including drainage and access for maintenance. The system's interfaces and responsibilities are recorded so that separate products are not assumed to form a coherent solution automatically. We consider how equipment would be inspected and serviced after the room is furnished. An arrangement that requires dismantling permanent finishes for ordinary maintenance should be reconsidered during design, when a practical access route can still be built into the scheme.
Test lightwells and the room they are meant to serve
Hackney's basement guidance considers the relationship between lightwells, the host building and retained garden space. We examine the actual street and site context rather than assuming that the whole front area can become an opening. A lightwell also needs to work with access, boundaries, drainage and the room below. These relationships are drawn in section so that the proposed space can be understood as a complete arrangement, not just as additional floor area.
For Tower Hamlets properties, the council's advice directs owners to check restrictions affecting flats and designated buildings. The proposed alteration and use are described accurately for the relevant assessment. Within the design, we review headroom, circulation, daylight, ventilation and the technical requirements associated with the intended activity. A utility space and a regularly occupied living room present different briefs. The documents should use consistent descriptions rather than calling the same space storage in one place and a bedroom elsewhere.
Sources: Hackney: basement and lightwell design guidance · Tower Hamlets: permitted development checks
Plan the construction route and the ongoing obligations
The feasibility review identifies how materials and excavated spoil can move through the property, where equipment can be accommodated and how retained areas are protected. Essential access and services need a workable arrangement. Those practical conditions can limit the extent or method of the work, and they are reviewed before the scheme becomes a fixed commitment. An excavation proposal is incomplete if its drawings explain the finished enclosure but leave its delivery route unresolved.
At completion we review the agreed installation, accessible equipment and relevant records, with the owner shown how to operate and maintain the systems. Final information reflects approved changes made during construction. Outstanding items are distinguished from work that was deliberately excluded. If the investigation does not support excavation or the proposed use, that finding is reported directly. We can consider repair of existing space or a revised brief, but no outcome is promised merely because basement conversions appear in the service list.
Before work begins
Basement conversions in Shoreditch: questions
Does Hackney allow every single-storey basement?
No automatic approval follows from that design principle. The current guidance addresses several matters, including the host building, lightwells, gardens and drainage. The individual site and proposal still need assessment. We use the guidance to frame the investigation rather than treating one criterion as a permission certificate.
Can Tower Hamlets properties use Hackney's basement rules?
They need the guidance and assessment applicable to their own authority. Shoreditch crosses the context of both councils, so we confirm the address first. Hackney's replacement SPD is useful for Hackney proposals within its scope, but it is not Tower Hamlets policy.
Is refurbishing an existing cellar always the same as excavating?
No. The scope identifies the existing enclosure and any proposed changes to depth, footprint, openings or use. That distinction informs the investigations and approvals. We describe the work accurately so a substantial ground alteration is not hidden behind the simpler language of an internal refit.
How is the proposed room use decided?
It is assessed against the available space, access, environmental conditions and relevant technical requirements. The brief should state the intended use consistently. We do not assume that every enclosed below-ground area can become a bedroom or living room simply by adding finishes and fittings.
What is included in maintenance planning?
The design identifies accessible components, controls and the practical route for inspection or replacement. Relevant product and system information is included at handover. Maintenance is considered before permanent finishes are completed, so essential equipment is not left concealed behind an enclosure that cannot be opened usefully.
Official sources
Hackney: current residential extensions and alterations SPD · Hackney: basement and lightwell design guidance · Tower Hamlets: East Shoreditch neighbourhood area · Tower Hamlets: permitted development checks
Sources checked on the dates recorded in the source register, most recently 5 November 2026. Maps, list entries and directions must be checked for the individual property and proposed work.