Senior Mechanical Estimator

Optima Site Solutions Ltd; Greater London; On-site; GBP 80,000 - 90,000; Full time

Benefits offered by this job

Employee-Owned Trust

Private Healthcare

Dental Insurance

Life Assurance

Company Pension

Annual Leave

Service Rewards

Financial Advice

TradePoint Discount

Professional Development

Job summary

Optima Site Solutions Ltd in London is seeking an experienced Senior Mechanical Estimator to lead the full mechanical tendering process from enquiry to final pricing. You will review drawings, prepare detailed cost estimates, and ensure bids are competitive and compliant with project requirements.

You will mentor the Junior Mechanical Estimator and coordinate with Project Managers, suppliers and commercial teams to support successful bids and project delivery.

Qualifications

• Proven experience as a Senior Mechanical Estimator or experienced Mechanical Estimator within construction, mechanical engineering or M&E building services.
• Strong technical understanding of HVAC, heating, cooling, chilled water systems, pipework and plantroom installations.
• Experience estimating complex mechanical projects, ideally with plant relocations, infrastructure upgrades or data centres.

Responsibilities

• Manage the full mechanical tendering process from enquiry to final pricing and submission.
• Prepare detailed cost estimates, take-offs, bills of quantities, labour assessments and tender submissions.
• Review drawings, specs and tender docs to define scope and technical requirements.
• Mentor and support the Junior Mechanical Estimator and collaborate with Projects/Commercial teams.

Skills

HVAC knowledge

Estimating complex projects

Tender management

Excel proficiency

Critical environments

Mentoring junior estimator

Education

Mechanical Engineering qualification

Apprenticeship completed

Building Services qualification

Tools

Estimating software

Digital take-off tools

Microsoft Office

Job description

Senior Mechanical Estimator

Location: London

Sector: Mechanical Engineering, M&E Building Services & Critical Infrastructure

Employment Type: Full-Time, Permanent

Salary: £80,000 - £90,000 per annum

Working Hours: 07:00 - 16:00

About the Company

Our client is an established mechanical and electrical engineering contractor delivering complex building services projects across the UK. Their work includes plant relocations, infrastructure upgrades and installations within data centres and live operational environments, where service continuity, careful planning and technically sound project delivery are essential.

Role Overview

We are recruiting for an experienced and commercially astute Senior Mechanical Estimator to join a growing Commercial team based in London.

The role involves managing the full mechanical estimating process, from initial tender enquiry through to final pricing and submission, ensuring estimates are accurate, competitive, technically compliant and commercially viable.

Working closely with clients, suppliers, subcontractors, Project Managers and commercial colleagues, you will contribute to securing new business and supporting successful project delivery.

You will also provide technical guidance and mentoring to an existing Junior Mechanical Estimator, reporting directly to the Estimating Manager and Commercial Director.

Key Responsibilities

• Manage the full mechanical tendering process, from initial enquiry and document review through to final pricing and submission.
• Prepare detailed cost estimates, quantity take-offs, bills of quantities, labour assessments, material schedules and tender submissions.
• Review mechanical drawings, specifications, schematics and tender documentation to establish project scope and technical requirements.
• Assess mechanical installation methods, construction sequencing, programme requirements and labour resources, particularly for live operational environments.
• Identify design discrepancies, scope gaps and commercial risks, raising RFIs and evaluating value engineering opportunities.
• Obtain, analyse and negotiate subcontractor and supplier quotations to ensure technical compliance and competitive pricing.
• Attend site surveys, tender walkthroughs, client meetings, commercial tender reviews and bid approval meetings.
• Support tender negotiations, post-tender clarifications and project handovers, ensuring commercial assumptions, exclusions and risks are clearly communicated.
• Work closely with Project Managers, Contracts Managers and Commercial teams to ensure estimates reflect practical installation requirements.
• Mentor and support the Junior Mechanical Estimator, reviewing estimates and contributing to improvements in estimating procedures, templates and cost databases.

Requirements

• Proven experience as a Senior Mechanical Estimator or experienced Mechanical Estimator within construction, mechanical engineering or M&E building services.
• Strong technical understanding of HVAC, heating, cooling, chilled water systems, pipework, plantroom installations and associated mechanical infrastructure.
• Demonstrable experience estimating complex mechanical projects, ideally involving plant relocations, infrastructure upgrades, data centres or other critical environments.
• Ability to independently manage mechanical tenders from initial enquiry through to final submission.
• Experience producing quantity take-offs, detailed cost estimates, labour calculations, material schedules and pricing breakdowns.
• Strong understanding of mechanical installation methods, construction sequencing, labour productivity and commercial tendering principles.
• Experience sourcing, evaluating and negotiating subcontractor and supplier quotations.
• Ability to interpret mechanical drawings, schematics, specifications and technical documentation.
• Strong proficiency in Microsoft Office, particularly Excel, alongside experience using mechanical estimating software and digital take-off tools.
• Completion of a recognised mechanical apprenticeship or possession of a relevant qualification in Mechanical Engineering, Building Services Engineering or a related discipline.
• Excellent numerical, analytical, organisational, communication and negotiation skills.
• Ability to manage multiple tenders, meet demanding deadlines and provide technical support to junior colleagues.
• Full UK driving licence and willingness to travel to client sites and project locations as required.

Desirable Experience

• Previous practical experience working on mechanical installations or within a site-based mechanical engineering role.
• Experience estimating plant replacement, plant relocation and mechanical infrastructure upgrade projects.
• Experience working within live operational sites, data centres or other critical environments where service continuity and careful project planning are essential.

What's on Offer

Salary: £80,000 - £90,000 per annum.

Employment: Permanent position within a growing Commercial team.

• Employee-Owned Trust (EOT): Eligibility to become a beneficiary following 12 months of continuous employment.
• Private Healthcare: Vitality healthcare cover for you and your dependants.
• Private Dental Insurance: Dental cover as part of the employee benefits package.
• Life Assurance: Financial protection for you and your loved ones.
• Company Pension: 7% employer contributions alongside 5% employee contributions.
• Annual Leave: 24 days' holiday plus UK Bank Holidays.
• Length of Service Rewards: Recognition and rewards for continued service.
• Private Financial Advice: Access to professional financial guidance.
• TradePoint Discount Scheme: Access to exclusive discounts.
• Professional Development: Ongoing training, skills development and career progression opportunities.

Who Should Apply

This position is suited to experienced Mechanical Estimators with strong technical knowledge of building services installations, proven commercial estimating capability and the confidence to independently manage complex tenders. Candidates with experience in plantroom installations, mechanical infrastructure upgrades, live operational environments or data centre projects will be particularly well suited to the role.