The Result
A contractor needed Building Control to accept the water‑efficiency submission first time. Previous phases had suffered delays from unclear evidence and mismatched product data.
ATSPACE prepared a complete, traceable water calculator evidence pack with verified product performance, plot‑specific schedules, and transparent assumptions. Building Control accepted the submission quickly, and the project avoided the common delay where handover files stall because water evidence is incomplete or inconsistent.
Project Snapshot
Service: Water efficiency calculations
Client: Main contractor (new build housing scheme)
Site: Parkside Meadow, 1–40 Birch Avenue, Worcester WR2 6SX
Development: 40 new build homes, staged completion
Programme stage: Building Control close‑out + handover pack assembly
Compliance driver: Approved Document G + Building Control evidence requirements
ATSPACE delivery: Water calculator submissions, evidence pack, product‑performance verification, plot tracking, close‑out summary
Team: ATSPACE compliance assessor + coordinator
Why Building Control Evidence Packs Get Rejected
Rejections are rarely about the calculation itself — they are about clarity and traceability.
Typical reasons:
- fittings schedule doesn’t match what is installed
- missing or unclear product evidence
- plot types grouped incorrectly
- different bathroom layouts treated as identical
- calculation submitted without supporting product data
The client wanted a pack that Building Control could approve without multiple rounds of queries.
What ATSPACE Was Asked To Do
- produce a Building Control‑ready water‑calculator evidence pack
- link every assumption to real, installed product specifications
- reduce end‑of‑project admin and information chasing
- align the submission with staged completions
What ATSPACE Did
Step 1: Plot‑type mapping + fittings‑schedule control
We mapped:
- plot types
- bathroom counts
- kitchen layouts
to ensure the correct schedule was applied to each dwelling.
Step 2: Product performance verification
We verified all water‑critical product data:
- WC flush volumes
- shower flow rates
- basin tap flow rates
- kitchen tap flow rates
- bath volumes
This ensured the calculator inputs were accurate and defensible.
Step 3: Evidence‑pack assembly
We built a pack that made Building Control’s job simple:
- plot schedule summary
- fittings schedule per plot type
- calculation outputs
- supporting product data sheets
- short note explaining any plot variations
Step 4: Close‑out & change control
Where substitutions were made, we:
- updated the schedule
- checked compliance remained intact
- adjusted the evidence pack
- prevented discrepancies between “modelled” and “installed”
Problems Faced — and How They Were Solved
Problem 1: Mixed procurement = inconsistent specifications
Different plots were receiving similar‑looking taps with different flow rates.
Solution:
We confirmed exact product usage per plot type and updated the evidence pack accordingly.
Problem 2: Incomplete product evidence
One bathroom package lacked clear performance data.
Solution:
We sourced the correct manufacturer information and integrated it consistently across the pack.
Problem 3: Plot variations risked confusing the submission
Some dwellings had different bathroom arrangements.
Solution:
We treated them as separate schedules instead of forcing them into a generic plot type.
Outcome
The Building Control evidence pack was accepted first time, with no follow‑up requests.
Project outcomes:
- fewer Building Control queries
- reduced admin at completion
- strong alignment between modelled and installed products
- smooth handover‑pack assembly
- clear, audit‑ready documentation
Common Mistakes This Project Avoided
- submitting calculations without supporting product data
- applying one fittings schedule across differing plot types
- relying on generic performance assumptions
- discovering substitutions after issuing the pack
- delaying sign‑off due to unclear or incomplete evidence
CTA
If you want Building Control to accept your water‑calculator submission without delays, ATSPACE will build a clear, accurate evidence pack linked to real installed products and deliver it in a format that is easy to review.
Ask for:
- Building Control‑ready water calculator evidence packs
- water‑efficiency calculations with verified product performance
- plot‑type mapping + schedule control
- support managing substitutions while maintaining compliance
Frequently Asked Questions
What does Building Control need to see?
A completed calculation tied to a clear fittings schedule and supported by product performance evidence.
Why do evidence packs get queried?
Because plot types and products aren’t clearly linked, or the evidence doesn’t support the values used.
Can ATSPACE support staged completions?
Yes — we align pack delivery with your programme so water compliance isn’t left until handover week.
