There were several Woods families in Inishlacken. In 1901 there were 4 and in 1911, 6 Woods households on the island. This looks to be your family in 1911:
http://www.census.nationalarchives.ie/pages/1911/Galway/Roundstone/Innishlacken_Island/452783/
And this is probably Martin with his parents in 1901:
http://www.census.nationalarchives.ie/pages/1901/Galway/Roundstone/Inishlasken_Island/1371788/
Martin’s father, Martin died on 22.5.1903 of peritonitis. You can see the death cert on this site:
https://churchrecords.irishgenealogy.ie/churchrecords/
Ignore the house numbers shown on the 2 censuses. They were the enumerator’s private numbering system. They varied from census to census, so property 1 in 1901 is not necessarily property 1 in 1911. Both the properties that Martin lived in, in 1901 and 1911 were single storey, with 2 windows at the front and with 2 to 4 rooms. The roof was either thatched or wooden. Probably thatched, in my opinion. I notice in the 1911 census that there are 2 houses in the name Martin Woods (9 and 15) and that no 9 was vacant.
There is a map of Innishlacken on the primary valuation site, showing 1 Woods household on the island in 1855 (plot 2d). However the map that accompanies it must date from a different period, a sit doesn’t show a 2d at all, and also shows a number of other properties on the island from a later period. However that might help you locate your family home in 1901 & 1911. The Griffiths revaluation records in the Valuation Office in Dublin should show which plot numbers on the island that Martin was living in in 1911, and which one his parents had in 1901. They may match the on-line map.
http://www.askaboutireland.ie/griffith-valuation/index.xml