Clean power supplier Good Energy has abandoned its plans to build a new corporate headquarters in Chippenham.
The firm said changes to the financial landscape caused by Covid-19, and the rise in home-working, have both contributed to the decision.
Instead, the firm will expand into another floor at Wiltshire Council's Monkton Park offices.
The move leaves Wiltshire Council and the Swindon and Wiltshire Local Enterprise Partnership looking for a new tenant at Sadlers Mead.
Good Energy will repay fees that the council has spent on designing the building.
Fran Woodward, people and customer operations director at Good Energy, said: "While this wasn't an easy decision for us to make, as the UK faces economic uncertainty following Covid-19, we need to ensure we're making the right investments for our future.
"Our entire workforce has been working from home effectively and productively. In this context, as a business that takes its environmental impact extremely seriously we have had to rethink our office workspace and how we can take a more digital and less carbon-intensive approach going forward, which will involve more remote and flexible working."
Cllr Philip Whitehead, leader of Wiltshire Council and cabinet member for economic development, said: "Of course, we're disappointed that Good Energy has chosen not to progress with this scheme, but we're pleased that the company is committed to keeping jobs in Chippenham.
"This site, which has great links to London due to its proximity to the station, remains an important strategic development area for the council, and we're working closely with SWLEP to explore new and exciting employment opportunities.
"We have worked closely with Good Energy throughout, and we will continue with this positive working relationship as they move into an extra floor in our Monkton Park offices."
SWLEP CEO Paddy Bradley said: "Although it's disappointing the current economic conditions mean Good Energy will not be moving forward with this project, the development remains a strategic priority for the area.
"Swindon and Wiltshire Local Enterprise Partnership continues to work with Wiltshire Council to explore other opportunities for the use of the site. Chippenham, with its strong connectivity, is well-placed to benefit from a development of this site."
Good Energy has been based in Chippenham for the past 20 years, and employs over 300 people in the town.