The scale of provision for WCs and wash hand basins is calculated using a standard formula documented in the local building code, which for the UK is BS 6465-1:2006.

Comments regarding the finishes of lounge washrooms have been posted here for a decade now - as the surface finishes started showing signs of wear and tear within a few months of the lounges opening. The materials selected were never sufficiently durable for the volume of traffic and suffered surface damage early in their life - with chipped doors, misaligned vanity panels etc. To be fair on BA, the facilities have received regular maintenance and the rate of deterioration has been stemmed.

The wet facilities were designed with flexibility in mind and despite their appearance, they were not built on the cheap - modular systems are generally more expensive to procure than conventional construction. Similarly, the entire plumbing system was designed for flexibility and adaptability and this too is expensive to install. BA's facilities team must be rueing the day these systems were selected because the higher capex has not resulted in lower opex - this is evident by the extensive patches and repairs we as users of the facilities see whenever we visit the lounges.

Aside from the washrooms and showers, the BA lounges are in pretty good nick. FF&E has been replaced as you'd expect in such heavily trafficked spaces.

Outside of the lounges, T5 is looking extremely good for its age. As a global showcase, a lot of money was poured into T5 - it was constructed to a high standard using quality materials. The building's shell is also well detailed. T2 by comparison suffered from extensive cost cutting; its build quality doesn't quite match the standards of T5. As an architect, the design and build compromises are all too apparent, but these are probably less noticeable to the lay person.