Plumbing Design Services | Water Supply & Drainage

Plumbing design

The engineering position

Gravity is not negotiable

Drainage needs fall, access and fixed connection levels. Designing it first — and reserving stack and riser positions with the architect — is what avoids pumped drainage and dropped ceilings later.

Sized to the method, not to habit

Water demand and drainage flows are calculated with the loading-unit or fixture-unit method the project's code requires, and the method is stated on every calculation.

Design responsibility

Design is carried out by BIMRACE's qualified engineers within the design responsibility written into the appointment. Where a jurisdiction requires a locally licensed engineer to sign, stamp or submit drawings and calculations, that engineer of record does so; we prepare and support the submission. Authority approvals are obtained by the appointed professionals.

Deliverables

What is actually produced and issued

Any of these can be appointed on their own or combined. Nothing here depends on buying the intelligence layer, which is not for sale in any case.

DeliverableWater demand and pipe sizing

Cold and hot water demand, pipe sizing, pressure and boosting requirements.

DeliverableDrainage design

Soil, waste and vent, sanitary drainage and stormwater design with falls and access points.

DeliverableTanks, pumps and hot water

Storage tank, pump and hot-water plant sizing and schedules.

DeliverableWater reuse

Rainwater harvesting, greywater and recycled-water system design where required.

DeliverablePlumbing schematics and risers

Riser diagrams and schematics for every system.

DeliverableCoordinated plumbing drawings

Layouts, plant rooms and sections drawn in Revit.

Catalogue scope

Every scope item, with its typical output

The full list from the BIMRACE service catalogue. Each item can be included or excluded in a proposal; the code is the one used in our scope documents.

PL-11Plumbing riser diagrams and schematics

Riser drawings and schematics.

PL-13Water tanks, pumps, valves and accessories

Equipment model and schedules.

PL-16Pipe sizing and hydraulic calculations

Calculation report and design schedules. Engineering design scope — only where design responsibility is explicitly agreed and supported by qualified engineers.

PL-17Water demand and drainage flow calculations

Calculation report. Engineering design scope — only where design responsibility is explicitly agreed and supported by qualified engineers.

PL-18Plumbing equipment schedules and connection details

Revit schedules and detail drawings.

How it runs

The sequence, and why it is in this order

Sequence is not a formality on this kind of work. Most of the expensive rework we are asked to fix was produced by doing step four before step two.

01

Brief and design basis

Building use, occupancy, design conditions, the codes the project must meet and the responsibility split — agreed and written down before any calculation is run.

02

Concept and system selection

System options compared for space, energy, capital and maintenance cost, with plant and riser space reserved early so the architecture can accommodate them.

03

Calculations and sizing

Loads, flows and sizes calculated to the stated method, with assumptions listed on the calculation rather than buried in it.

04

Layouts in the model

The design is drawn directly in Revit, so sizes, routes and equipment data live on the elements and coordination starts from the design, not after it.

05

Coordination and review

Federated clash and clearance checks against architecture, structure and the other services; an independent engineering review before issue.

06

Issue and support

Design drawings, calculations, schematics and schedules issued under revision control, with support through tender, approvals and construction queries.

What we need to start

The inputs that decide whether a start is a real start

Missing any of these is survivable. Not knowing which of them are missing is not, so we establish it at enquiry stage rather than at forty per cent.

Architectural model with sanitary layouts and room data
Occupancy and fixture schedule, or the basis to derive one
Connection points, invert levels and mains water pressure
The plumbing code the project must comply with
Water reuse or sustainability targets, if any

Send us what you have

AI & automation

Where AI and automation apply to this work

AI is used throughout our delivery workflow, and an engineer reviews every output. Every line carries its real status.

AIAI fixture schedule extractionLive

Fixture counts and locations extracted from architectural layouts as the basis for loading-unit calculations.

AIAI design checksLive

Drainage falls and pipe sizes screened against the design criteria before the engineer's review.

AutomationFall and gradient validationLive

Modelled drainage gradients tested against the design falls.

AutomationSizing reconciliationLive

Calculated pipe sizes compared with the model.

Scope boundary

What this appointment does not include

Published because a scope boundary discovered at month three is a dispute, and the same boundary stated at enquiry stage is just information.

Drainage adoption applications and utility negotiations stay with the client's appointed party.
CCTV survey of existing drainage is not included.
Local stamping and authority approval stay with the engineer of record where required.

Request a quote

Get a quote: Plumbing design

Tell us the building, the stage and what you need. An engineer replies within two working days with approach, deliverables and a fee basis.

What a useful quote needs. Building type and approximate area, the disciplines, the project stage, and which drawings or models exist. If you have them ready, the full enquiry form takes file uploads.

NDAs. We sign before drawings or models are shared, as a matter of course.

FAQ

Questions we are asked at enquiry stage

Which method do you use for plumbing sizing?

The loading-unit or fixture-unit method required by the project's code — for example BS EN 806/12056, IPC/UPC or India's National Building Code — stated on the calculation.

Do you design rainwater harvesting and greywater systems?

Yes, including storage, treatment space allowance, pumps and distribution, where the project requires them.

Can you size water tanks and booster pumps?

Yes. Storage, booster and transfer pump duties are calculated and scheduled.

MEP engineering designAll four disciplines together. Plumbing BIMModelling an existing plumbing design. Fire protection designShared water storage and pump rooms.

Plumbing and drainage design services