21. Is there a limit on in-kind donations to political parties?

Electoral Act 1997 Section 22 (2) For the purposes of this Part—(a) “donation” means any contribution given for political purposes by any person, whether or not a member of a political party, to a political party, a member of either House of the Oireachtas, a representative in the European Parliament or a candidate at a Dáil, Seanad or European election and includes all or any of the following, namely— (i) a donation of money, (ii) a donation of property or goods, (iii) conferring the right to use, without payment or other consideration, indefinitely or for a specified period of time, any property or goods, (iv) the supply of services without payment or other consideration therefor, (v) the difference between the commercial price and the price charged for the purchase, acquisition or use of property or goods or the supply of any service where the price, fee or other consideration is less than the commercial price, or (vi) in the case of a contribution made by a person in connection with an event organised for the purpose of raising funds for a political party, a member of either House of the Oireachtas, a representative in the European Parliament or a candidate at a Dáil, Seanad or European election, the proportion attributable to that contribution of the net profit, if any, deriving from the event.

In-kind donations are treated the same as cash donations and the same rules and limits apply. 
See Standards in Public Office Commission. 2015. Guidelines for Political Parties Steps to be taken concerning donations and prohibited donations, p. 9.