About
One office, fifty-four people
Founded in Reading in 2011 on the argument that a fifty-person consultancy could do better technical work than a five-thousand-person one. Fifteen years later we still think that, with rather more evidence.
Our mission
Thornfield exists to make environmental evidence useful while a design can still change.
Ines Kowalczyk started the practice in 2011 after eleven years as a hydrologist at a large multidisciplinary firm, where the recurring frustration was structural rather than personal: the technical work was good, and it arrived too late to affect anything. By the time a flood risk assessment reached a design team, the layout was fixed and the assessment’s only remaining function was to justify it.
The practice was six people in a room above a shop on Kennet Side for the first three years. It is now fifty-four in the same building, three floors up. There is no regional structure and no plan for one — a second office would double the management overhead and halve the number of people who know each other well enough to catch each other’s mistakes.
We are employee-owned as of 2022, with 60% held in trust. That was partly succession planning and partly a hedge: an independent environmental consultancy of this size is an obvious acquisition target, and being bought by a multinational is the single most reliable way to become the thing we set up not to be.
- 2011
- Founded in Reading
- 54
- Staff, one office
- 14
- Environmental statements coordinated
- 9.2
- Years, average tenure
Who runs it
Four people you will actually meet
Ines Kowalczyk
Managing director
Hydrologist by training. Founded the practice in 2011 after eleven years at a multidisciplinary firm, on the argument that a fifty-person consultancy could do better technical work than a five-thousand-person one.
Nadia Farsi
Head of ecology
Nine ecologists, four survey licences, and the person who will tell you in January what you cannot survey until June.
Owen Brackley
Head of acoustics
Corporate member of the Institute of Acoustics. Spent two years as an expert witness before deciding he preferred fixing things earlier.
Marcus Ayeni
Head of land & water
Chartered geologist. Has talked three local authorities out of unnecessary remediation and lost that argument twice, which he will also tell you about.
Our own footprint
The awkward paragraph
An environmental consultancy publishing a carbon figure is obliged to publish an honest one. Ours for the year to March 2026 was 148 tonnes CO₂e across scopes 1, 2 and 3, of which 96 tonnes was business travel and 71 of those were survey mileage.
Survey mileage is the hard part and we have not solved it. Dusk bat surveys finish after the last train, three sites in a day is common, and a hybrid van fleet has cut the figure by about 14% since 2023 rather than the 40% we told ourselves it would. We are not offsetting the remainder and calling it net zero, because a consultancy that assesses other people’s carbon claims should not be making a weak one of its own.
What has worked: 100% renewable electricity on a supply-backed tariff since 2019, a four-day core week that removed roughly a fifth of commuting, and refusing work beyond two hours’ drive unless it can be done in one visit. What has not: a cycle-to-site scheme nobody used, and a paperless reporting target we missed for four years running before admitting the surveyors need paper in the rain.
Get in touch
Tell us about the site before you buy it
A twenty-minute call at option stage is the cheapest environmental advice you will ever take, and occasionally it is the advice not to proceed.