Engineering consultancies in construction: their disciplines and their role

The disciplines

Structure	Sizing the load-bearing structure: foundations, frame, floors. Load calculations, reinforcement, connections. Deliverables: calculation notes, structural drawings, reinforcement schedules.
Mechanical services	Designing and sizing heating, ventilation, cooling, sanitary plumbing and fire protection. Deliverables: schematic drawings, service layouts, thermal calculation notes.
Electrical	Designing the power installations, high and low voltage, lighting, and the data systems: networks, building management, access control, alarms, CCTV.
Thermal and energy	Regulatory studies for new and existing buildings, dynamic thermal simulation, energy performance calculation, and studies for environmental certification.
External works	Designing roads and services: surface water, foul drainage, potable water, buried electrical services, roads and landscaping.
Geotechnics	Ground investigation, characterising the foundations, recommendations for earthworks. Missions from preliminary to construction stage under the national standard.
Acoustics	Noise impact studies, sound insulation between dwellings, room acoustics. Mandatory for certain building types.
Construction economics	Producing the estimates, the pricing schedules and bills, analysing the contractors' offers, and monitoring the finances on site. Sometimes in house within the architectural practice, sometimes outsourced.

Their place in the design team

In a design consortium the architect is generally the lead consultant, the client's single interlocutor, with the engineers as co-contractors. Each is contractually bound to the client but coordinated by the architect.

That organisation imposes a technical coordination role on the architect which should not be under-estimated: making sure the different engineers' solutions are compatible, that the openings are correctly transferred to the drawings, and that the interfaces between packages are clearly defined in the tender documents.

How to choose

Comparable references	Has the consultancy worked on comparable projects in type, size and complexity? References are the first selection criterion.
Availability and responsiveness	An overloaded consultancy that misses drawing deadlines can block the whole design programme. Assess the team's current workload.
Current regulatory competence	Regulations move fast. Make sure the consultancy commands the latest normative developments applicable to the project.
Tools and methods	A consultancy working in building information modelling on the same platform as the architect makes coordination easier and reduces interface errors.
Insurance	Check the consultancy carries professional and ten-year liability cover for the type of appointment.

The critical interfaces

The most expensive errors and conflicts in construction arise at the interfaces between disciplines. The most frequent points of vigilance are:

Structure with mechanical services: the openings in floors and walls for ventilation ducts. An omission or a mispositioning is expensive on site.
Structure with external works: anchoring buried services into the foundations and the substructure levels. Coordination is indispensable before earthworks begin.
Mechanical services with electrics: the electrical supply to the mechanical plant, heat pumps, air handling units. Capacities and connections must be coordinated very early.
Thermal with architecture: thermal bridging at the junctions between structure and envelope. The architectural design must build in the thermal constraints from the outline stage to avoid expensive reworking later.

Cost estimates, pricing schedules, development appraisals, summary notes. Produce in minutes the deliverables you prepare manually today. First project free. → quostra.com

The appointments described correspond to French practice. The scope of competence varies with the practice and with the contracts signed.