UK regulations will require all new homes to have Zero net carbon emissions by a year . These are the most ambitious targets in the world , according to experts . Jefferson , of the Zero Carbon Hub , said : `` The target is without doubt the most challenging in the world . '' UK , Germany and Sweden have built more sustainable homes so far , say environmentalists .
UK regulations will require all new homes to have Zero net carbon emissions by a year . These are the most ambitious targets in the world , according to experts . UK , Germany and Sweden have built more sustainable homes so far , say environmentalists .