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Pi Labs
Pi Labs

Building Physics Engineer



Posted on Monday, April 22, 2024

Building Physics Engineer

Job Description

Application deadline: 14th June 2024
Target start date: Summer 2024
Location: Hybrid with 2 days per week at our co-working space in Clerkenwell, London, UK
Hours: Full time with core hours 10am - 4pm
Origination: New role
Language: English
Compensation: base salary: 45-70k based on experience + generous share options

Meet Kestrix: the ‘Google Maps of Heat Loss’

Globally, 10% of emissions come from heating and cooling buildings, and nearly 6 retrofits must happen every minute between now and 2050 for net zero targets to be met. Luckily, tech (like good old insulation) to fix the problem exists. But when resources required for such a herculean undertaking – labour, financial, time – are limited, how can we be sure we are starting with the right buildings? Allocating the right budgets? Doing the work well?
Today, we can’t. That’s right: there is no scalable, cost-effective way of knowing reliably how heat is lost across the millions of buildings we all live, work, and play in – let alone how to fix it and how much fixes will cost. This leads to bottlenecks – lost time, wasted resources, and overspent budgets for those executing on building decarbonisation projects now – like housing providers, local governments, contractors, and energy companies.
Kestrix is here to solve retrofit’s data problem, enabling the world to retrofit its buildings at speed and scale. How are we going to do this?
We are building retrofit’s data layer. The ‘Google Maps of Heat Loss’, Kestrix uses thermal drones and AI to construct 3D heat loss models of buildings and reveal retrofit opportunities in seconds, without needing site visits. Our dataset is already streamlining planning, prioritisation, and verification of retrofits not just for single homes, but for hundreds (and soon thousands) of buildings in the portfolios of leading social housing providers.
We’ve raised over $1M in equity and grant funding, and are now looking for an experienced building physicist to help take Kestrix to the next level of technical leadership in the area of building decarbonisation.
So what are you waiting for?
I hope to see your application.
Best wishes
CTO, co-founder & hiring manager

The role

We’re looking for our first building physicist, reporting to CTO and co-founder Matt. The building physicist will be responsible for developing scalable building thermal modelling approaches, including the possibility to apply machine learning on individual buildings that can be applied at city scale.
A successful candidate is a self-starter, keen to challenge the status quo and passionate about applying their technical and analytical skills to solve the urgent problem of building decarbonisation in a fast paced and dynamic startup environment.

Our Values

At Kestrix, we work by 5 guiding principles:
🔍 We are curious. We ask questions (of customers and each other) and really listen to answers.
📏We are problem-solvers. We embrace an experimental approach to work. Fail, learn, adapt.
🤝We are generous. We go out of our way to help others and always look out for one another.
🌈We are respectful. We value others’ time, as well as opinions, and treat others respectfully.
👭We trust each other. We assume good intent, focus on output, and see mistakes as learnings.

Job Responsibilities

Lead Kestrix’s development of building thermal modelling, leveraging Kestrix’s unique scalable and quantitative thermal imaging data to simulate individual buildings across whole cities.
Prototype 3D dynamic thermal models to assess energy use and thermal performance using standard tools such as IES or EnergyPlus.
Develop software tools and algorithms to integrate simulations into Kestrix’s platform. This could include training and development of machine learning models, for an interested and capable candidate.
Collaborate with the software engineering team to deploy simulations into production.
Participate in product and solution design discussions, contributing your ideas and insights to ensure the accuracy, reliability, and performance of Kestrix’s solution.
Develop and maintain a deep understanding of the business goals and objectives of Kestrix, aligning technology strategies and initiatives to support and drive these objectives forward.
Conduct research and stay up to date with the latest advancements and trends in building physics, and related fields, leveraging this knowledge to enhance Kestrix's technologies and stay ahead.

Your Qualifications/Experience

Critical requirements

Graduate degree in STEM subject
5+ years experience as a building physicist or building thermal modeller, of which 2 years in a commercial organisation, particularly in relation to thermal comfort, passive design and real operational energy assessments.
Have a good knowledge of the impact of building design on thermal performance and apply this to building energy modelling work.
Experience with dynamic simulation software such as IES or EnergyPlus.
Experience in analysing a range of different building typologies, construction types, and methods of improving their thermal characteristics.
2+ years experience in coding in Python for data analysis and customising simulations.
A passion for sustainable building design and reducing the carbon emissions of the built environment.
Strong problem-solving skills and the ability to work independently and as part of a team in a fast-paced startup environment.
Demonstrate attention to detail and show pride in the work produced
Excellent communication skills, with the ability to effectively collaborate and communicate technical ideas to both technical and non-technical stakeholders.

Nice to haves

PhD is building physics or related subject.
Experience developing machine learning models to optimise building performance modelling and analysis.
An understanding of SAP / RdSAP software.
Experience with parametric rhino/grasshopper workflows.
Experience developing and deploying software in a commercial environment.


25 days paid time off + the week between Christmas Day and New Years (with flexibility to shift for those of non-Christian religious backgrounds) + standard England public holidays, and a day off on your birthday.
Hybrid working with 2 days per week at our co-working space in Clerkenwell, London.
Pension contributions (3% of salary)
Flexible working outside core working hours
Optional monthly team socials

Interview Process

The process will have 3 rounds, the outcome of each will be assessed by Kestrix who will notify you of the outcome by email:
Application form and CV submission here
1: First round interview with hiring manager (30 mins)
2: Role-specific case study (in-person)
3: Interview with other co-founder
Offer & take up 2 references