There were few surprises announced in the 2021 budget for the sale and leasing of properties.
As had been flagged in advance, the enhanced help to buy scheme which was due to expire on 31 December 2020 has been extended until the end of 2021 at the enhanced rate of up to €30,000 (or 10% of the purchase price if lower). That enhanced rate had been introduced as part of the Covid reliefs from 23 July 2020.
The stamp duty on residential and commercial purchases and leases would appear to have been left unchanged. 
The Stamp Duty Residential Development Refund Scheme has also been extended from houses in which construction commences before 31 December 2021 to those in which works start before 31 December 2022. This scheme provides that a purchaser of non-residential property, who subsequently constructs a residential property can obtain a partial refund of the non-residential stamp duty originally paid.